Open market review: what an altnet’s declaration decides
In short: Open market review declarations state where a supplier will build, and Building Digital UK (BDUK) spends Project Gigabit subsidy only on premises no supplier has claimed. The September 2026 National Rolling Open Market Review closes on 1 October 2026. BDUK classifies declared premises Grey, Black or Under Review and excludes them; it monitors Under Review premises for three years and re-maps them as White if the plans fall away.
A fixed network builder anywhere in the UK has until 1 October 2026 to tell BDUK, premises by premises, where it will build over the next three years. BDUK decides on the strength of that return whether to fund a competing gigabit network into the same streets. BDUK opened the September 2026 National Rolling Open Market Review on 1 September 2026. It is the third such review this year, and its outcome may inform the next Project Gigabit procurements in England and Wales.
No provision of the Communications Act 2003 compels a response to the request, and Ofcom’s role in the subsidy scheme is advisory. A supplier that says nothing risks BDUK re-using its last national return without update. A supplier that declares build it cannot evidence risks BDUK reclassifying the premises and putting them out to tender.
How BDUK classifies premises for subsidy
BDUK will subsidise build only to premises it classifies as White: no gigabit-capable network exists and none is likely within three years. Grey premises have one qualifying network available or due within three years, Black premises have two or more from different suppliers, and Under Review premises are those where a supplier has reported coverage or plans that BDUK has not yet verified, or where evaluators are confident of delivery but see remaining risk or gaps in the evidence. The four categories are set out in section 4 of the request for information and in BDUK’s subsidy control classification guidance.
BDUK cites section 13A of the Industrial Development Act 1982 as the legal basis for its spending, and section 31 of the Local Government Act 2003 for local authority contributions, in section 6 of the Detailed Overview of the Gigabit Infrastructure Subsidy Scheme (version 0.7). BDUK has run the national review every four months, in January, May and September, since January 2022. Suppliers submit a premises-level dataset in the Annex A format, a supporting evidence pack on BDUK’s template and, if they wish, a statement of the wholesale products they would like to see on any subsidised network.
What an open market review declaration commits a supplier to
A supplier that declares planned build in the open market review makes no contractual promise to deliver it. Under section 4 of the request for information, Under Review premises “will be subject to continued monitoring and verification of supplier plans within the 3 year period by BDUK”, BDUK “may request commitment from the supplier that significant progress is made within 3 years” and, if the plans fall away, “these premises will be mapped as eligible and form part of the proposed IAs”, the intervention areas put out to tender. BDUK may also reclassify premises previously determined Grey or Under Review where the evidence no longer meets the earlier categorisation (section 10). A supplier that overstates its plans loses the exclusion from subsidised competition, and BDUK may then pay a competitor to build in the same footprint.
BDUK assesses planned coverage “solely on the suite of evidence you provide in your Supporting Evidence Pack”, testing technology, deliverability and financial viability. That review extends to business plans, deployment plans and the terms of financing, including repayment terms, expected return on investment and dependency on public subsidy. Each premises with planned coverage must carry a ready-for-service date, a design stage from a list of eight, and a funding stage that distinguishes funding planned from funding committed, the latter meaning ring-fenced money with no further conditions on drawdown. BDUK asks that evidence be no more than six months old.
BDUK will automatically re-use the previous submission of a supplier that responded to a previous national review but not to this one, unless the supplier instructs otherwise, subject to evaluation and possible reclassification (section 11). A supplier whose only prior returns were to local reviews gets no carry-over, and BDUK asks a supplier that wants to rely on its last national return to confirm that in writing before 1 October 2026 (section 9).
BDUK treats response data as commercially confidential but may share “some/all of your response data with our professional advisors and/or local bodies, Ofcom and Department for Business and Trade Subsidy Control Branch” (section 9). BDUK publishes the outcome at premises level, showing White, Grey and Black combined, and Under Review, so the classification of every premises becomes public even though the supplier behind it and its financing do not. This year the assessed outcome covers England and Wales only, because review activity is still running in Scotland and Northern Ireland.
The conditions that follow subsidy
A supplier that wins a Gigabit Infrastructure Subsidy contract for White premises takes on obligations that outlast the build. Under section 10.8 of the Detailed Overview it must offer passive and active wholesale access to the subsidised network “under fair and non-discriminatory conditions to all competent third party operators who request it”, for a minimum of seven years, or indefinitely for new passive infrastructure. If the supplier or the network is sold within that period the access obligation transfers to the buyer. A supplier that also sells retail services must make a wholesale reference offer available to competitors at least six months before retail launch and keep separate accounts for wholesale and retail. Under section 10.13 an access seeker who cannot reach agreement may ask Ofcom to investigate.
BDUK recovers subsidy through three mechanisms set out in section 10.14 of the Detailed Overview and its clawback guidance. Under implementation clawback BDUK trues up the subsidy at the end of the build. Under take-up clawback BDUK recovers, for the rest of the contract term, a share of a contractually agreed quarterly profit per customer for every customer above the number in the supplier’s financial model. BDUK monitors the contract for a minimum of seven years and a maximum of fifteen (section 10.5).
The Gigabit Broadband Voucher Scheme carries different conditions. Vouchers of up to £4,500 per premises are grants to the beneficiary, paid by BDUK direct to the registered supplier once the connection is delivered, under the Supplier Terms and Conditions (version 10.1, 5 June 2025). For a business beneficiary the voucher is minimal financial assistance under sections 36 and 37 of the Subsidy Control Act 2022 and counts against that enterprise’s £315,000 threshold over three financial years. The supplier terms contain no wholesale access obligation and no exclusivity: another supplier may propose a project in the same area after BDUK has approved one (clause 7.11). Under Schedule 1 BDUK excludes any premises that is part of another government subsidy programme or that BDUK assesses as likely to get gigabit coverage without subsidy, which is where the voucher scheme and the open market review meet: under section 5 of the request for information, planned voucher build is typically classified White, an issued voucher makes the premises Under Review, and a claimed voucher makes it Grey.
| Condition | Gigabit Infrastructure Subsidy contract | Gigabit Broadband Voucher Scheme |
|---|---|---|
| Subsidy basis | Section 13A Industrial Development Act 1982; transparency stated against the Trade and Cooperation Agreement in a document that predates the Subsidy Control Act 2022, in force since 4 January 2023 (Detailed Overview, sections 6 and 10.15) | Grant to the beneficiary, paid to the supplier; minimal financial assistance to a business beneficiary under Subsidy Control Act 2022 ss 36 and 37, £315,000 over three financial years (Supplier Terms, Part A and Schedule 1) |
| Wholesale access | Passive and active access on fair and non-discriminatory terms; minimum seven years, or indefinite for new passive infrastructure; transfers on sale (section 10.8) | None |
| Retail supplier duties | Reference offer available to competitors six months before retail launch; accounting separation (section 10.8) | Gigabit package at a fair market price; minimum twelve-month customer contract (Schedule 2; clause 9.6) |
| Recovery | Implementation, take-up and additional-services clawback (section 10.14); monitoring seven to fifteen years (section 10.5) | Cost caps, sample audits, withdrawal or recovery on fraud, malpractice or error (clause 14) |
| Exclusivity | Subsidy limited to premises classified White (request for information, section 4); no exclusivity term in the Detailed Overview | None; another supplier may propose a project in the same area (clause 7.11) |
| Ofcom’s role | Advisory on access conditions and pricing; investigation at an access seeker’s request (section 10.13) | Supplier, or for a wholesaler every ISP on its network, must belong to an Ofcom-approved ADR scheme (clause 6.1) |
Implications for altnets, lenders and buyers
An altnet that declares three years of build has excluded that footprint from subsidised competition for as long as its evidence holds. The same declaration exposes its financing terms to BDUK, its advisers, Ofcom and the Department for Business and Trade, and puts its planned footprint on a published map. The three evidence tests in paragraph 10.1 apply to every supplier, whether it builds on its own duct or on Openreach’s under the regulated product described in the altnet PIA post.
For a lender, the open market review return is a statement of the borrower’s build plan made to a government body that will read the loan documents. Repayment terms, covenants and drawdown conditions inform whether BDUK classifies funding as committed. For a buyer of an altnet, the target’s past returns record what it told BDUK and when, and where BDUK has re-mapped premises from Under Review to White the target has lost an exclusion it once held. A buyer of a network built under a Gigabit Infrastructure Subsidy contract takes on the wholesale access obligation, which transfers with the network, and the take-up clawback, which runs for the contract term and continues after completion. Buyers in the consolidation described in the nexfibre and Netomnia post now meet that transfer provision as a standard diligence question; our regulatory due diligence page sets out the scope.
Viewpoint
I read the open market review as the point at which an altnet’s build plan stops being a private document. The return goes to a body that will test the financing behind it, share it with the subsidy control authorities and publish the resulting map. A declaration is only worth making where the evidence pack can survive the deliverability and funding tests in paragraph 10.1 of the request for information. A premises reclassified from Under Review to White becomes a public record that the plan, or the evidence for it, did not hold.
The request for information is inconsistent on what happens when a supplier stays silent. Section 2 says a previous national return “may be reused, but it may not”; section 11 says BDUK “will automatically re-use your previous submission”. A supplier that sends the written confirmation that section 9 invites removes the doubt for itself.
The obligations that follow subsidy outlast the review that created them. Ofcom’s fibre access conditions under the Telecoms Access Review 2026-31, described in the Openreach FTTP pricing post, bind BT and end when Ofcom revokes them; BDUK’s bind the subsidised supplier and its successors for the contract term. Ofcom advises on access disputes; BDUK enforces the subsidy conditions.
Frequently asked questions
When does the September 2026 open market review close?
Responses to the September 2026 National Rolling Open Market Review are due by 1 October 2026. BDUK opened the review on 1 September 2026 and accepts clarification questions throughout that period. The assessed outcome for this review covers England and Wales only, because open market review and public review activity is still running in Scotland and Northern Ireland.
Is an open market review declaration legally binding?
No. A declaration of planned build creates no contractual obligation to deliver. BDUK classifies the premises Grey, Black or Under Review, monitors Under Review premises for three years, may ask the supplier to commit to significant progress, and re-maps the premises as White and eligible for subsidy if the plans fall away. BDUK may also reclassify premises where the evidence no longer meets the earlier categorisation.
What happens if a supplier does not respond?
Under section 11 of the request for information, BDUK will automatically re-use the previous submission of a supplier that responded to a previous national review but not this one, unless the supplier instructs otherwise, subject to evaluation and possible reclassification. A supplier whose only prior returns were to local reviews gets no carry-over. BDUK asks suppliers who want to rely on a previous national return to confirm this in writing before the closing date.
Does a Gigabit Infrastructure Subsidy contract require open access?
Yes. Every bidder must commit to passive and active wholesale access on fair and non-discriminatory conditions for a minimum of seven years, or indefinitely for new passive infrastructure (section 10.8 of BDUK’s Detailed Overview). The obligation transfers to a buyer if the supplier or the network is sold within that period. Voucher-funded connections under the Gigabit Broadband Voucher Scheme carry no equivalent access obligation.
For advice on an open market review return, a Gigabit Infrastructure Subsidy contract or the subsidy conditions attaching to a fibre network you are financing or buying, contact Rob Bratby at Bratby Law.
