UK Space Agency C-LEO Call 3 National Only 2026: Up to £42 Million for UK Low Earth Orbit Satellite Communications Projects, Stage One Closing 7 September

UK Space Agency C-LEO Call 3 National Only 2026: Up to £42 Million for UK Low Earth Orbit Satellite Communications Projects, Stage One Closing 7 September

The UK Space Agency’s Connectivity in Low Earth Orbit (C-LEO) Call 3: National Only is a substantial 2026 grant opportunity for UK companies and research organisations developing satellite-communications technology for high-volume low Earth orbit constellations. The call makes up to £42 million available and expects to support a small number of sizeable projects, with the guidance indicating awards of roughly £4 million to £25 million per project. Funding is not a simple unrestricted subsidy: applicants must provide a credible contribution of their own, and the eligible grant percentage depends on the type and size of each enterprise or research partner.

The first application stage closes at 12:00pm GMT on Monday 7 September 2026. Only applicants that pass Stage One can submit the more detailed Stage Two package, which is due at 12:00pm GMT on 11 November 2026. Successful projects are expected to begin in calendar quarter one or two of 2027 and finish no later than 31 March 2030. This makes the call relevant to companies that already have a technically credible development plan and need public support to move from a working prototype toward industrialisation, qualification, or demonstration.

Key details at a glance

The award figures are the call’s overall expectations, not a guaranteed minimum or maximum for every proposal. A project should request the amount it can justify against a defined work plan, eligible costs, matched contribution, and measurable route to market.

What the C-LEO call is designed to fund

C-LEO Call 3 responds to the growth of high-volume satellite constellations and the need for communications hardware and software that can be produced, deployed, and supported at scale. The UK Space Agency is looking for proposals that strengthen the UK’s position in the supply chain while producing a clear technical and commercial advance. A general space project is not enough; the work must connect directly to one or more of the call’s listed technology areas.

The eligible areas are on-board regenerative processing, active antennas, optical links, networking and routing, and user terminals. A strong proposal will explain the specific capability being improved, the bottleneck preventing wider deployment, and why the proposed project is the right intervention at this point in development. The guidance gives priority to projects entering at TRL 4 to 6 and aiming to reach TRL 7 or higher. Higher-TRL proposals may also be considered, but the application still needs to show a tangible improvement in readiness or a demonstrable advance in an engineering method or technical capability.

The call is therefore a better fit for a company with a tested subsystem, a credible laboratory demonstrator, or a validated engineering approach than for an early idea with no evidence. The proposal should be able to name the starting point, the technical work packages, the test or demonstration environment, and the evidence that will establish the end point. If your technology is below TRL 4, the guidance says the application will be ineligible and will not be assessed.

Who can apply and how partnerships work

Every proposal must be led by a UK-based organisation. A commercial company must be registered at Companies House, and a successful applicant must have a UK bank account because grant payments are made in pounds sterling. Project partners are also expected to be UK-based unless the UK Space Agency agrees otherwise. Organisations may participate in multiple applications, but an organisation may lead only one proposal in this call.

Universities, non-profit research and technology organisations, Catapults, public-sector organisations, public-sector research establishments, research council institutes, other eligible research organisations, and charities can participate under the call’s research and knowledge-dissemination rules. A research organisation should be non-profit distributing and must explain how it will disseminate the results of its research. Universities undertaking non-economic research can receive up to 80% of full economic cost; other qualifying research organisations may receive up to 100% of eligible costs. No more than 30% of the total grant value can be awarded to research organisations.

Research and public-sector partners cannot simply be included as a route to higher support while receiving an economic benefit that is inconsistent with their status. Public-sector organisations and charities seeking 100% funding must be undertaking research, plan to disseminate results, avoid claiming costs already paid from public funds, and avoid economic activity or economic benefit from the project. The eligibility boundary should be discussed internally before a consortium is finalised.

Subcontractors are treated differently from project partners. They do not have to provide match funding, but subcontracting costs must be included on a cost-recovery basis, and no more than 50% of the total grant award can be spent on subcontracting. If non-UK suppliers are essential, the need should be declared in the initial application. The guidance warns that non-UK spending is unlikely to score well against equivalent UK-based activity unless its value is clearly demonstrated.

Match funding and the real cost of the grant

The call requires every project to include a compelling level of matched funding. The applicable rate depends on the enterprise size and whether the project qualifies for a collaboration uplift. Without the uplift, the maximum grant contribution is 45% of eligible project costs for a small enterprise, 35% for a medium enterprise, and 25% for a large enterprise. With the collaboration uplift, those figures rise to 60%, 50%, and 40% respectively.

The uplift requires collaboration between enterprises where at least one is an SME, or between an enterprise and a research and knowledge-dissemination organisation that has the right to publish its own research results. Each enterprise in a consortium must provide the relevant share of match funding. For example, a project involving a medium enterprise and two small enterprises may use the uplift, but the medium enterprise and each small enterprise still have their own contribution rates to meet.

This structure changes how a team should plan its budget. Do not begin with the largest grant number and work backward. Begin with the work required to reach the technical and commercial milestone, assign eligible costs to the organisations that will incur them, calculate each participant’s intervention rate, and then confirm that the private or institutional contribution is actually available. The guidance also notes that Minimum Financial Assistance can cover up to £315,000 over a rolling three-fiscal-year period without match funding, but awards under that and related regimes must be declared and cumulated. That exception is unlikely to replace the normal matched-funding analysis for a multi-million-pound C-LEO project.

Application process and required materials

C-LEO is a two-stage process. For Stage One, only the lead organisation submits the application. The organisation can use the online Stage One form linked from the official guidance or submit the Word form by email to [email protected] with the subject line “C-LEO Call 3: National Only.” A reference number should be issued after an emailed submission. The form must arrive by noon GMT on 7 September; the guidance states that late applications will not be accepted and that no extension is permitted.

Stage One asks four equally weighted questions, each with a 500-word limit: strategic fit, value for money, catalysing investment, and innovation. This is a concise case for entry into the second stage, not a shortened version of the entire engineering plan. It should establish that the project is in scope, the technology is sufficiently mature, public funding is necessary, private investment or follow-on demand is plausible, and the proposed output is genuinely novel.

Applicants invited to Stage Two must submit the Stage Two form plus the required annexes by 11 November 2026. The package includes a budget breakdown spreadsheet, a national security questionnaire, an overheads spreadsheet where applicable, and a grant applicant checklist. The budget must break costs down by work package and individual labour costs, identify equipment, map milestones to requested funding, and show the amount requested for each deliverable. Grant funding is paid in arrears against agreed completed milestone deliverables, so a proposal needs a realistic cash-flow plan as well as a technical plan.

The templates matter. Altered templates, incomplete applications, or submissions that exceed the specified limits can be rejected or ignored in assessment. The guidance specifies single-spaced text, a minimum 12-point Arial font, and minimum 1.5 cm margins for the application material. Treat formatting as an eligibility control, not as a cosmetic preference.

Timeline from application to delivery

The call opened on 20 July 2026. Questions for Stage One must be sent by 24 August, with the latest UK Space Agency response scheduled for 31 August. Stage One outcomes and invitations to Stage Two are expected by 2 October. Invited teams then have until 28 October to submit Stage Two questions, and the latest response is scheduled for 4 November.

Stage Two closes at noon GMT on 11 November. Final outcomes are expected by 16 December, grant-agreement negotiations are scheduled to finish by 1 April 2027, and projects are expected to start in Q1 or Q2 of 2027. Every project must end by 31 March 2030. If the project needs a licence under the Space Industry Act 2018 or Outer Space Act 1986, the guidance says the necessary licence must be obtained before the licensable activity begins; early engagement with the Civil Aviation Authority is recommended.

The delivery obligations continue after award. Recipients should expect a kick-off meeting, written progress reports, regular reviews that are expected to be monthly, quarterly review meetings, milestone evidence, benefits and lessons-learned updates, and a final review. Successful applicants must provide baseline data and participate in outcome monitoring during and after delivery. The final report may be published on the UK Space Agency website, so confidential intellectual property should be separated from the public, non-confidential account of results.

How to prepare a competitive proposal

Start with a one-page technology and evidence map. State the current TRL, the test or demonstration that supports it, the gap the project will close, and the evidence that will prove the next TRL. Then connect every work package to a measurable output. “Develop the platform” is too broad; “complete environmental qualification of the active-antenna subsystem and demonstrate the target performance in the named test configuration” is the kind of statement that can be costed and reviewed.

Build the commercial case alongside the technical case. The Stage One criteria give 25% to strategic fit, 25% to value for money, 25% to catalysing investment, and 25% to innovation. The guidance specifically asks how the proposal strengthens UK capabilities, why public funding is needed, what economic benefits and follow-on investment could result, and what outputs are novel. Identify customers, likely adopters, procurement or qualification barriers, relevant supply-chain relationships, and the decision points that could turn a successful demonstration into revenue or additional private investment. Do not use market-size figures without a source or an explanation of how they relate to your product.

For Stage Two, prepare a fuller version of the same argument. Each of the first four criteria has a 2,000-word limit, while project management and benefits have 1,000-word limits. Assign a named owner to delivery, risk, regulatory work, partner coordination, and benefits measurement. Make the match contribution visible by participant, and show that the project can survive the reimbursement timing of milestone payments. Where equipment or overheads are significant, explain why the resources are necessary, how the cost was calculated, and what happens to the equipment after the project.

Finally, ask an independent reader who understands both spacecraft systems and commercialisation to challenge the proposal. Can they tell what will be demonstrated, who will use it, why the UK benefits, and what happens if the most optimistic test result is not achieved? A clear fallback path and a credible risk owner are more persuasive than a list of unqualified assurances.

Common mistakes to avoid

The most serious mistake is scope drift. A project can be important to space but still fail the call if it does not address on-board processing, active antennas, optical links, networking and routing, or user terminals. A second is starting below the stated TRL threshold or failing to define the evidence for a readiness advance.

Budget errors are another predictable problem. Applicants sometimes show the grant request but not the participant-level match, treat subcontractors as partners, include profit margins in cost-recovery figures, or assume that ordinary business overhead is automatically eligible. The call also limits travel and subsistence to no more than 10% of total grant value and subcontracting to no more than 50% of the award. Check both limits before the narrative is final.

Do not leave regulatory work until contracting. Spectrum compliance, licensing, national-security questions, export or supply-chain constraints, and the treatment of intellectual property can affect the schedule and the partnership agreement. Also avoid submitting multiple proposals as lead, changing the official templates, adding unrequested appendices, or waiting until the deadline day to discover that your organisation or submission route is not ready.

Frequently asked questions

Is this an open call or an invitation-only award?

It is an open call with a two-stage process. Any eligible UK organisation can submit Stage One, but only proposals that pass Stage One are invited to submit Stage Two.

Can a non-UK company lead the project?

No. The lead must be a UK-registered entity registered with Companies House. Partners are also expected to be UK-based unless the UK Space Agency agrees otherwise.

Does the call fund an early idea?

Not normally. Proposals below TRL 4 are ineligible. The target range is TRL 4 to 6, with a tangible improvement toward TRL 7 or above, although higher-TRL proposals may be considered.

Is match funding required for every proposal?

Yes, the call requires a credible element of match funding. The permitted grant share depends on enterprise size, collaboration, and the applicable subsidy-control rules.

When would funded work begin?

Projects are expected to start in Q1 or Q2 of 2027 after outcomes and grant-agreement negotiations. All projects must finish by 31 March 2030.

Where should applicants ask questions?

Questions about the call should be sent to [email protected]. Applicants should first use their own finance or research office for costings and internal approvals, and should seek specialist legal or regulatory advice where subsidy control or licensing issues require it.

Official links and next steps

Read the UK Space Agency C-LEO Call 3 guidance for applicants, including the official forms, assessment criteria, grant terms, and annex instructions. Before applying, confirm the lead organisation’s Companies House status, assemble the technical and commercial partners, calculate the intervention rate for each participant, and secure evidence of the matched contribution.

The practical next step is to draft the four Stage One answers against the 500-word limits and have the lead organisation’s authorised submitter review them. If the project is a fit, make the route from today’s tested technology to a 2027–2030 deployment or industrialisation result unmistakable. The deadline is noon GMT on 7 September 2026, and a technically promising project can still be excluded if the form, eligibility evidence, match-funding logic, or submission format is incomplete.