Sovereign AI - Proof of concept
UK registered businesses can apply for a share of up to £1.6 million for the development of Proof of Concept demonstrators of AI technologies with state of the art performance. This is to support the UK’s AI sovereignty objectives.
- Opening date:
- Closing date:
Contents
Summary
Description
Innovate UK, part of UK Research and Innovation, will invest a minimum of £1.6 million. This funding is from Innovate UK, part of UK Research and Innovation and is subject to a sufficient number of high quality applications being received.
We reserve the right to adjust funding allocations for any of our competitions under exceptional circumstances, for example, in response to changes in policy, portfolio funding considerations, or broader government funding decisions.
These projects will be to validate highly scalable proof of concept stage AI technologies that will support the UK’s AI sovereignty objectives. Your project can deliver and validate the performance of novel architectures or subsystem components, utilising computer simulation or synthetic data when full system capability cannot be achieved within the project delivery.
The aim of this competition is to demonstrate Proof of Concept of AI technologies with state of the art performance in areas of strategic importance to UK. This will ensure that frontier AI technologies are developed in the UK, safeguarding UK’s future economic growth and security and geostrategic influence.
Your proposal must deliver one or more of the following:
Proof of Concept of architecture or subsystem component
technical validation of capability of system or subsystem component
frontier AI performance that delivers new to the world capability or state of the performance of existing capability
ability of architecture and business model to scale
demonstrate a clear path for access to data
demonstrate strategy to access compute infrastructure and quantify requirement for compute
In applying to this competition, you are entering into a competitive process. This competition has a funding limit, so we may not be able to fund all the proposed projects. It may be the case that your project scores highly, but we are still unable to fund it.
Our experience from similar competitions suggests that you could have 25% chance of success.
This competition closes at 11am UK time on the deadline stated in this Innovate UK competition brief. We cannot guarantee other government, or third party sites will always show the correct competition information.
Funding type
Grant
Project size
Your project’s total eligible costs must be between £50,000 and £120,000.
Accessibility and Inclusion
We welcome and encourage applications from people of all backgrounds and are committed to making our application process accessible to everyone. This includes making reasonable adjustments, for people who have a disability or a long-term condition and face barriers applying to us.
You can contact us at any time to ask for guidance.
We recommend you contact us at least 15 working days before this competition’s closing date to allow us to put the most suitable support in place. The support we can provide may be limited if you contact us close to the competition deadline.
You can contact Innovate UK by email or call 0300 321 4357. Our phone lines are open from 9am to 12pm and 2pm to 5pm UK time, Monday to Friday (excluding bank holidays).
Eligibility
Who can apply
Your project
Your project must:
have total costs between £50,000 and £120,000
last between 1 and 3 months
carry out all of its project work in the UK
intend to exploit the results from or in the UK
start by 1 of January 2026
end by 31 March 2026
Projects must always start on the first of the month, even if this is a non-working day. You must not start your project until your Grant Offer Letter has been approved by Innovate UK. Any delays within Project Setup may mean we need to delay your project start date.
You must only include eligible project costs in your application. See our overview of eligible project costs. For specific guidance, see the eligibility section in this competition.
If your project’s total costs falls outside of our eligibility criteria, you must provide justification by email to support@iuk.ukri.org at least 10 working days before the competition closes. We will decide whether to approve your request.
If you have not requested approval or your application has not been approved by us, you will be made ineligible. Your application will then not be sent for assessment.
Lead organisation
To work alone your organisation must be a UK registered business of any size.
More information on the different types of organisation can be found in our Funding rules.
Subcontractors
Subcontractors are allowed in this competition.
Subcontractors can be from anywhere in the UK and you must select them through your usual procurement process.
You cannot use subcontractors from overseas.
All subcontractor costs must be justified and appropriate to the total eligible project costs.
Subcontracting costs are limited to 20% of total project costs.
Number of applications
A business can only lead on one application.
Sanctions
This competition will not fund you, or provide any financial benefit to any individual or entities directly or indirectly involved with you, which would expose Innovate UK or any direct or indirect beneficiary of funding from Innovate UK to UK Sanctions. For example, through any procurement, commercial, business development or supply chain activity with any entity as lead, partner or subcontractor related to these countries, administrations and terrorist groups.
Use of animals in research and innovation
Innovate UK expects and supports the provision and safeguarding of welfare standards for animals used in research and innovation, according to best practice and up to date guidance.
Applicants must ensure that all of the proposed work within projects, both that in the UK and internationally, will comply with the UKRI guidance on the use of animals in research and innovation.
Any projects selected for funding which involve animals will be asked to provide additional information on welfare and ethical considerations, as well as compliance with any relevant legislation as part of the project start-up process. This information will be reviewed before an award is made.
Previous applications
You cannot use a previously submitted application to apply for this competition.
We will not award you funding if you have:
failed to exploit a previously funded project
an overdue independent accountant’s report
failed to comply with grant terms and conditions
Innovate UK may withhold a grant payment at any time if you have any outstanding sums due to us in relation to other projects.
Subsidy control (and State aid where applicable)
This competition provides funding to enterprises using the Research, Development and Innovation Streamlined Subsidy Scheme.
The Research, Development and Innovation Streamlined Scheme can be viewed on the subsidy database here: SC10780.
This is in line with the Subsidy Control Act 2022. Further information about the Subsidy requirements can be found within the Subsidy Control Act 2022 (legislation.gov.uk)
Innovate UK is unable to award organisations that are considered to be in financial difficulty. We will conduct financial viability and eligibility tests to confirm this is not the case following the application stage.
EU State aid rules now only apply in limited circumstances. Please see the Windsor Framework to check if these rules apply to your organisation.
In the ‘Project details’ section of your application you will be asked questions to indicate if State Aid or Subsidy applies to your organisation.
Further Information
If you are unsure about your obligations under the Subsidy Control Act 2022 or the State aid rules, you should take independent legal advice. We are unable to advise on individual eligibility or legal obligations.
You must always make sure that the funding awarded to you is compliant with all current Subsidy Control legislation applicable in the United Kingdom.
This aims to regulate any advantage granted by a public sector body which threatens to, or distorts competition in the United Kingdom or any other country or countries.
Funding
A minimum of £1.6 million has been allocated to fund innovation projects in this competition. This is subject to a sufficient number of high quality applications being received. Funding will be in the form of a grant.
We reserve the right to adjust funding allocations for any of our competitions under exceptional circumstances, for example, in response to changes in policy, portfolio funding considerations, or broader government funding decisions.
If your organisation’s work on the project is commercial or economic, your funding request must not exceed the limits below. These limits apply even if your organisation normally acts non-economically but for the purpose of this project will be undertaking commercial or economic activity.
Choose the applicable categories below for the Research, Development and Innovation Streamlined Subsidy Scheme:
Category 1 Feasibility studies
Funding available for your eligible project costs of:
up to 70% if you are a micro or small organisation
up to 60% if you are a medium sized organisation
up to 50% if you are a large organisation
Category 2 Industrial research projects
Funding available for your eligible project costs of:
up to 70% if you are a micro or small organisation
up to 60% if you are a medium sized organisation
up to 50% if you are a large organisation
For more information on company sizes, please refer to the company accounts guidance.
If you are applying for an award funded under State aid Regulations, the definitions are set out in the European Commission Recommendation of 6 May 2003.
Innovate UK may revoke our decision to provide funding without notice if government commitment for this initiative is withdrawn.
Objectives
Your proposal
The aim of this competition is to demonstrate Proof of Concept of AI technologies with state of the art performance in areas of strategic importance to UK. This will ensure that frontier AI technologies are developed in the UK, safeguarding UK’s future economic growth and security and geostrategic influence.
Your technology must have in principle the ability to scale at pace, but you are not required to prove or validate scalability. We are expecting projects to deliver technologies at Technology Readiness Level (TRL) 3 to 5.
Your project must demonstrate the ability of your technology to work in principle. You can focus in demonstrating at least the key critical component and you can utilise synthetic and simulated data for validation. You need to demonstrate how you will achieve state of the art performance if capability already exists, or new to the world capability if the technology is further developed.
Your proposal must deliver one or more of the following:
Proof of Concept of architecture or subsystem component
technical validation of capability of system or subsystem component
frontier AI performance that delivers new to the world capability or state of the performance of existing capability
ability of architecture and business model to scale
demonstrate a clear path for access to data
demonstrate strategy to access compute infrastructure and quantify requirement for compute
Portfolio approach
We want to fund a variety of projects across different technologies, markets, technological maturities, research categories and themes. We call this a portfolio approach.
Specific themes
Your project must focus on one or more of the following:
Fundamental AI research:
embodied AI, sensory motor grounded systems
safe by design architectures, multi agent systems, agentic AI
novel architectures including neuro symbolic, neuromorphic and biologically inspired models
AI for materials discovery of:
material discovery and property prediction
generative and physics-ML hybrid models
automated workflows and closed loop discovery
This list is not intended to be exhaustive
AI for biosciences and health:
genomics and multi omics models for medicines discovery
foundational patient level health models
foundational bioscience models
scalable and secure monitoring and evaluation of health AI
AI for defence and national security:
real time and near real time systems
distributed and decentralised systems
specialised models for critical infrastructure management and cybersecurity
AI aided design for:
AI accelerator chips
neuromorphic hardware
optical backplanes
Research categories
We will fund feasibility projects and industrial research projects, as defined in the guidance on categories of research.
Projects we will not fund
We are not funding projects that:
are literature review studies
do not require research and development
are not delivering measurable objectives
are unable to scale in principle
We cannot fund projects that are:
dependent on export performance, for example, giving a subsidy to a baker on the condition that it exports a certain quantity of bread to another country
dependent on domestic inputs usage, for example, giving a subsidy to a baker on the condition that it uses 50% UK flour in their product
Dates
15 August 2025
Online briefing event: join at 11.30
(Briefing slides will be available to download from Supporting Information after the event)
14 October 2025
Applicants notified
1 January 2026
Project start from
How to apply
Before you start
You must read the guidance on applying for a competition on the Innovation Funding Service before you start.
Before submitting, it is the lead applicant’s responsibility to make sure:
that all the information provided in the application is correct
your proposal meets the eligibility and scope criteria
all sections of the application are marked as complete
You can reopen your application once submitted, up until the competition deadline. You must resubmit the application before the competition deadline.
What we ask you
The application is split into four sections:
Project details.
Application questions.
Finances.
Project Impact.
Accessibility and Inclusion
We welcome and encourage applications from people of all backgrounds and are committed to making our application process accessible to everyone. This includes making reasonable adjustments, for people who have a disability or a long-term condition and face barriers applying to us.
You can contact us at any time to ask for guidance.
We recommend you contact us at least 15 working days before this competition’s closing date to allow us to put the most suitable support in place. The support we can provide may be limited if you contact us close to the competition deadline.
You can contact Innovate UK by email or call 0300 321 4357. Our phone lines are open from 9am to 12pm and 2pm to 5pm UK time, Monday to Friday (excluding bank holidays).
1. Project details
This section provides background for your application and is not scored.
Do not include any website addresses (URLs) in your answers.
Application team
Decide which people from your organisation will work with you on the project and invite those people to help complete the application.
Application details
Give your project’s title, start date and duration.
Research category
Select the type of research you will undertake.
Project summary
Describe your project briefly and be clear about what makes it innovative. We use this section to assign the right experts to assess your application.
Your answer can be up to 400 words long.
Public description
Describe your project in detail and in a way that you are happy to see published. Do not include any commercially sensitive information. If we award your project funding, we will publish this description. This can happen before you start your project.
Your answer can be up to 400 words long.
Scope
Describe how your project fits the scope of the competition. If your project is not in scope, it will not be sent for assessment. We will tell you the reason why.
Your answer can be up to 400 words long.
2. Application questions
The assessors will score all your answers apart from questions 1 to 5. You will receive feedback for each scored question. Find out more about how our assessors assess and how we select applications for funding.
You must answer all questions.
You must not include any website addresses or links (URLs) in your answers. If you do, your application will be made ineligible.
Question 1. Applicant location (not scored)
You must state the name and full registered address of your organisation and subcontractors working on your project.
We are collecting this information to understand more about the geographical location of all applicants.
Your answer can be up to 100 words long.
Question 2. Animal testing (not scored)
Will your project involve any trials with animals or animal testing?
You must select one option:
Yes
No
We will only support innovation projects conducted to the highest standards of animal welfare.
Further information for proposals involving animal testing is available at the UKRI Good Research Hub and NC3R’s animal welfare guidance.
Question 3. Permits and licences (not scored)
Will you have the correct permits and licences in place to carry out your project?
We are unable to fund projects which do not have the correct permits or licences in place by your project start date.
You must select one option:
Yes
No
In the process of being applied for
Not applicable
Question 4. International Collaboration (not scored)
Does your proposed work involve any international collaboration or engagement?
You must provide details of any expected international collaboration or engagement. You must include a list of the names and the countries, any international project co-leads, project partners, visiting researchers, or other collaborators are based in. You must also include details of any subcontractors or service providers.
If your proposed work does not involve international collaboration or engagement, your answer must confirm this.
Your answer can be up to 100 words long.
Question 5. Trusted Research and Innovation (not scored)
You must explain if your proposed project work relates to UKRI’s Trusted Research and Innovation (TR&I) Principles, including:
a list of any dual-use (both military and non-military) applications to your research
a list of the areas where your project is relevant to one or more of the 17 areas of the UK National Security and Investment (NSI) Act
whether an export control license is required for this project under the academic export control guidance and the status of any applications
a list of any items or substances on the UK Strategic Export Control List
If your proposed work does not relate to UKRI’s TR&I Principles, your answer must confirm this.
We may ask you to provide additional TR&I information at a later date, in line with UKRI TR&I Principles and funding terms and conditions.
Your answer can be up to 400 words long.
Question 6. Need or challenge
What is the business need, technological challenge, or market opportunity behind your innovation?
Explain:
how your project if successful can create strategic advantage to the UK
the business need, technological challenge or market opportunity
whether you have identified any similar innovation and its current limitations, including those close to market or in development
any work you have already done to respond to this need, for example, if the project focuses on developing an existing capability or building a new one
the wider economic, social, environmental, cultural or political challenges which are influential in creating the opportunity, such as incoming regulations
Your answer can be up to 400 words long.
Question 7. Approach and innovation
What approach will you take and where will the focus of the innovation be?
Explain:
the technical work you expect to deliver during the project duration
how you will validate project outcomes within project timeframe
what is the state of the art performance you seek to demonstrate
what are the KPIs you seek to achieve and demonstrate with the project
what are the requirements for computer and training data to develop your technology further if your project is successful
the freedom you have to operate
how it will make you more competitive
Your answer can be up to 800 words long.
You can submit one appendix to support your answer. It can include diagrams and charts. It must be a PDF no larger than 10MB. It can be up to four A4 pages and must be legible at 100% zoom.
Question 8. Team and resources
Who is in the project team and what are their roles?
Explain:
the roles, skills and experience of all members of the project team that are relevant to the approach you will be taking
the resources, equipment and facilities needed for the project and how you will access them
the details of any vital external parties, including subcontractors, who you will need to work with to successfully carry out the project
any roles you will need to recruit for
Your answer can be up to 400 words long.
You can submit one appendix, with a short summary of the main people working on the project to support your answer. It must be a PDF no larger than 10MB. It can be up to two A4 pages and must be legible at 100% zoom.
Question 9. Market awareness and business model scalability
What does the market or markets you are targeting look like?
Describe:
how this technology will be further developed and scaled
how will you scale your business model if successful
the target markets for the project outcomes and any other potential markets, either domestic, international or both
the size of the target markets for the project outcomes, backed up by references where available
what non-technical resources are required to further develop and scale at pace this technology
the structure and dynamics of the target markets, including customer segmentation, together with predicted growth rates within clear timeframes
the target markets’ main supply or value chains and business models, and any barriers to entry that exist
the current UK position in targeting these markets
If your project is highly innovative, where the market may be unexplored, describe or explain:
what the market’s size might be
how your project will try to explore the market’s potential
Your answer can be up to 400 words long.
Question 10. Outcomes and route to market
How are you going to grow your business and increase long term productivity as a result of the project?
Explain:
your current position in the markets and supply or value chains outlined, and whether you will be extending or establishing your market position
your target customers or end users, and the value to them, for example, why they would use or buy your product
your route to market
how you are going to profit from the innovation, including increased revenues or cost reduction
how the innovation will affect your productivity and growth, in both the short and the long term
how you will protect and exploit the outputs of the project, for example through know-how, patenting, designs or changes to your business model
your strategy for targeting the other markets you have identified during or after the project
If there is any research organisation activity in the project, describe:
your plans to spread the project’s research outputs over a reasonable timescale
how you expect to use the results generated from the project in further research activities
Your answer can be up to 400 words long.
Question 11. Wider impacts
What impact might this project have outside the project team?
Describe and, where possible, measure the economic benefits from the project such as productivity increases and import substitution, to:
the UK economy
external parties
customers
others in the supply chain
broader industry
Describe and, where possible, measure:
any expected impact on government priorities
any expected environmental impacts, either positive or negative
any expected regional impacts of the project
Describe any expected social impacts, either positive or negative, on, for example:
quality of life
social inclusion or exclusion
jobs, such as safeguarding, creating, changing or displacing them
education
public empowerment
health and safety
regulations
diversity
Your answer can be up to 400 words long.
Question 12. Project management
How will you manage your project effectively?
Explain:
the main work packages of your project, indicating who is assigned and the total cost of each one
your approach to project management, identifying any major tools and mechanisms you will use to get a successful and innovative project outcome
the management reporting lines
your project plan in enough detail to identify any links or dependencies between work packages or milestones
Your answer can be up to 400 words long.
You must submit a project plan or Gantt chart as an appendix to support your answer. It must be a PDF no larger than 10MB. It can be up to two A4 pages and must be legible at 100% zoom.
Question 13. Risks
What are the main risks for this project?
Explain:
the main risks and uncertainties of the project, including the technical, commercial, managerial and environmental risks
how you will mitigate these risks
any project inputs that are critical to completion, such as resources, expertise, and data sets
any output likely to be subject to regulatory requirements, certification, ethical issues and other requirements identified, and how you will manage this
Your answer can be up to 400 words long.
You must submit a risk register as an appendix to support your answer. It must be a PDF no larger than 10MB. It can be up to two A4 pages and must be legible at 100% zoom.
Question 14. Added value
How will this public funding help you to accelerate or enhance your approach to developing your project towards commercialisation? What impact would this award have on your organisation?
Explain:
what advantages public funding would offer your project, for example: appeal to investors, more partners, reduced risk or a faster route to market
the likely impact of the project outcomes on your organisation
what other routes of investment or means of support you have already engaged with and why they were not suitable
how any existing or potential investment or support will be used in conjunction with the grant funding
what your project would look like without public funding
how this project would change the R&D activities of all the organisations involved
Your answer can be up to 400 words long.
Question 15. Costs and value for money
How much will the project cost and how does it represent value for money for the team and the taxpayer?
In terms of your project goals, explain:
your total eligible project costs
the grant you are requesting
how you will finance your contribution to your project
how this project represents value for money for you and the taxpayer
how it compares to what you would spend your money on otherwise
any subcontractor costs and why they are critical to your project
Your answer can be up to 400 words long.
3. Finances
You must complete your own project costs, organisation details and funding details in the application.
For an overview on what costs you can claim, see our project costs guidance. Note this is general guidance, for specific guidance please see the eligibility section in this competition. You can also view our application finances video.
4. Project Impact
This section is not scored but will provide background to your project.
You must complete the Project Impact questions before being able to submit the application.
More information can be found in our Project Impact guidance and by viewing our Impact Management Framework video.
Innovate UK complies with the requirements of UK GDPR and the Data Protection Act 2018, and is committed to upholding data protection legislation, and protecting your information in accordance with data protection principles.
Assessment
Your application will be reviewed by three independent assessors based on the content of your application and their skills or expertise relevant to your project. All of the scores awarded will count towards the total score used to make the funding decision unless you are notified otherwise.
You can find out more about our assessment process in the General Guidance.
Your submitted application will be assessed against these criteria:
Sovereign AI - Proof of concept assessor guidance for applicants.pdf
Supporting information
Background and further information
The rapid advancement of AI capabilities creates enormous opportunities for economic growth, security and geostrategic influence. The AI opportunities Action Plan outlines key priorities that will ensure the UK not only benefits from advancements in AI, but also is home to UK grown national champion AI companies with frontier AI capabilities. This will safeguard that the UK has sovereign access to frontier AI systems and be in a position to influence the future of AI’s values, safety and governance.
The Sovereign AI Unit has an ambitious mandate to strengthen the UK’s AI capabilities with up to £500 million of funding. It will do this by investing in UK companies, creating and developing UK AI assets and enables and making the UK the partner of choice for Frontier AI companies.
The Sovereign AI - Proof of concept funding opportunity aligns with the objectives of the Sovereign AI Unit mandate and seeks to inspire ambitious UK businesses to demonstrate innovation capability within principle ability to scale and set the foundations for the creation of the frontier AI systems of the future.
Research, Development and Innovation Streamlined Scheme Information
This award is being offered under the Research, Development and Innovation Streamlined Subsidy Scheme in accordance with section 10(4) of the Subsidy Control Act 2022.
Projects funded must meet the following definitions:
Category 1: Feasibility study
The evaluation and analysis of the potential of a project, which aims at supporting the process of decision making. This is done by objectively and rationally uncovering its strengths and weaknesses, opportunities and threats, as well as identifying the resources required to carry it through and ultimately its prospects for success.
Category 2: Industrial research
The planned research or critical investigation that is aimed at the acquisition of new knowledge and skills for developing new products, processes or services. It can also be for projects that are aimed at bringing about a significant improvement in existing products, processes or services.
This would include digital products, processes or services, in any technology, industry or sector (including, but not limited to, digital industries and technologies, such as super-computing, quantum technologies, block chain technologies, artificial intelligence, cyber security, big data and cloud technologies).
Industrial research comprises the creation of component parts of complex systems. It may include the construction of prototypes in a laboratory environment or in an environment with simulated interfaces to existing systems as well as of pilot lines. Where necessary, this would be for the industrial research and notably for generic technology validation.
Briefing recording and slides
Briefing recording and slides will be available to download here after the briefing event.
What happens if you receive a grant offer
If you have passed your initial assessment and have received an email with a grant offer, you will be asked to complete the project set up process on the Innovation Funding Service (IFS).
We will ask for information that will allow us to undertake mandatory checks on your organisation and the eligibility of your costs, as well as review the documentation for your project.
You must follow the unique link embedded in your email notification. This takes you to your project's dedicated IFS Set Up portal, where we gather the information required to set up your project.
Watch our videos on what steps there are before a project starts and how successful applicants receive their funding or read more about Project Setup in our General guidance.
If your application is unsuccessful
If you are unsuccessful with your application this time, you can view feedback from the assessors. This will be available to you on your IFS portal following notification.
Sometimes your application will have scored well, and you will receive positive comments from the assessors. You may be unsuccessful as your average score was not above the funding threshold or your project has not been selected under the portfolio approach if this is applied for this competition.
We would like to remind you that eligible non-funded business can still benefit from fully funded and bespoke support from the Innovate UK Business Growth service.
Support for SMEs from Innovate UK Business Growth service
Innovate UK Business Growth helps innovation focused businesses make the best strategic choices and access the right resources, in order to grow and ultimately achieve scale.
Our innovation and growth specialists provide our fully funded and bespoke support to clients nationwide. Please visit the service’s website to discover whether you could benefit from this advisory support, which is available to Innovate UK funded and non-funded businesses alike.
Protecting your innovation
A Secure Innovation campaign has been developed to help founders and leaders of innovative startups protect their technology, competitive advantage, and reputation.
This was developed by UK’s National Protective Security Authority (NPSA) and the National Cyber Security Centre (NCSC).
Data sharing
This competition is operated by Innovate UK.
Innovate UK is directly accountable to you for its holding and processing of your information, including any personal data and confidential information. Data is held in accordance with our own policies.
Innovate UK may also share any relevant information submitted and produced during the application process concerning your application with Innovate UK’s national and regional UK third parties and partners who may contact you. For more information see how we handle grant applicant and grant holder data.
Innovate UK and Innovate UK Business Connect will be data controllers for personal data submitted during the application.
Innovate UK Business Connect Privacy Policy
Innovate UK complies with the requirements of UK GDPR and the Data Protection Act 2018, and is committed to upholding data protection legislation, and protecting your information in accordance with data protection principles.
The Information Commissioner’s Office also has a useful guide for organisations, which outlines the data protection principles.
Contact us
If you need more information about how to apply or you want to submit your application in Welsh, email support@iuk.ukri.org or call 0300 321 4357.
Our phone lines are open from 9am to 12pm and 2pm to 5pm UK time, Monday to Friday (excluding bank holidays).
Innovate UK or any of our partners will not tolerate abusive language in any written or verbal correspondence, applications, social media or any other form that might affect staff.