List X approval is granted to a single named site, cleared by the Ministry of Defence to hold material classified SECRET or above. List N is a separate scheme, regulated by the Office for Nuclear Regulation and covering the civil nuclear supply chain. Neither is a security classification.
Both appear in bids for secure government work, and both are regularly described wrongly in supplier responses. The schemes have different regulators and different legal authority, so approval under one tells a buyer nothing about the other.
List X is a Ministry of Defence approval granted to a specific site. That site is cleared to hold material classified SECRET or above. The approval attaches to the facility rather than the organisation occupying it. The Ministry of Defence publishes the security requirements a List X site has to meet.
Suppliers often write this up as List X accreditation, and the wording varies more than the substance does. What varies usefully for a buyer is whether the claim names the premises it applies to. A bid written at company level has described an organisation when the approval was granted to an address.
The Ministry of Defence increasingly uses Facility Security Clearance for this approval, and both terms are in circulation. A supplier’s older capability statement may say List X while a recent contract schedule says Facility Security Clearance, and the two describe the same thing.
The newer term is the more accurate of the two, because it names the unit being assessed. Read either label as a statement about premises rather than about the supplier as a whole.
Not automatically. List X approval is granted site by site, so a contractor working from four premises may hold it at one address. A company-level claim leaves the cleared address unstated. Ask which site appears on the approval and compare that with where your contract would be delivered from.
The gap matters most where delivery is split across locations. Work scoped into a cleared facility can drift towards an office or a support team somewhere else, and the approval does not travel with it. Where a supplier holds List X sites in more than one place, each was granted on its own assessment and each has its own scope.
The same question applies down the supply chain. Where part of the delivery sits with a subcontractor, that firm’s premises were assessed separately or not at all, and the arrangement is easier to change while the subcontracting is still being agreed.
The Office for Nuclear Regulation is the statutory regulator for civil nuclear security in Great Britain. Its authority over List N comes from Regulation 22 of the Nuclear Industries Security Regulations 2003, and ONR publishes the scheme and how organisations enter it.
The scheme covers organisations in the civil nuclear supply chain that hold Sensitive Nuclear Information, shortened by ONR to SNI. The threshold is OFFICIAL-SENSITIVE: SNI or above. Approval here is granted to the organisation, which is the structural difference from the site-based approach the Ministry of Defence takes.
No. The Office for Nuclear Regulation regulates List N. It approves organisations in the civil nuclear supply chain to hold Sensitive Nuclear Information at OFFICIAL-SENSITIVE: SNI or above. The Ministry of Defence runs a separate scheme, List X, which clears individual sites.
The confusion is common enough to watch for. The shared list naming does most of the work, and a supplier writing about either scheme from a distance tends to bundle the two into a single defence regime. A response describing List N as a Ministry of Defence approval has not been through the ONR process, which is a useful early read in an evaluation.
The UK has three security classifications: OFFICIAL, SECRET and TOP SECRET. They describe the sensitivity of the information itself and are set out in the Cabinet Office’s Government Security Classifications Policy.
Both schemes record something else. Each states that a site or an organisation has been assessed and cleared to handle information at a given level. The classification belongs to the information, and the approval belongs to whoever was assessed.
A bid claiming a “List X classification” has the terms confused. That is often a sign the security response was written some distance from the approvals it describes, which is worth catching before award rather than after.
The two schemes gate different categories of information, each under its own regulator and its own regulation. Where defence material has to be held at a cleared site, ask for List X whatever nuclear approvals a supplier holds. Where the work involves Sensitive Nuclear Information, the ONR approval is the one that applies.
Ask a supplier presenting List X to name the approved site and the level it is cleared to. Then check that address against where the contract would actually run from, including any part of the work sitting with a subcontractor.
Ask a supplier presenting List N which part of the civil nuclear supply chain it holds the approval for. That sets the approval against the work it was granted for and shows whether the scope reaches your requirement.
What either answer confirms is narrow. A named site, or a named organisation, met the requirements of that scheme at the point of assessment. How the supplier manages information security across the rest of the business is a separate question, with its own certificates and its own evidence.
Both questions belong in the written stage of a procurement rather than in a meeting. A bid describing the two schemes as one Ministry of Defence regime has been through neither process, and that shows up faster in a written response than in a presentation.
Both approvals sit alongside the wider set of certificates a buyer checks before award. The AxisTwelve guide to the security accreditations public sector suppliers need covers the rest of that stack and how to verify each one.
The regulators differ and so does the information covered. The Ministry of Defence grants List X, clearing one named site to hold material classified SECRET or above. The Office for Nuclear Regulation grants List N, allowing an organisation in the civil nuclear supply chain to hold Sensitive Nuclear Information at OFFICIAL-SENSITIVE: SNI or above.
Yes. Facility Security Clearance is the term the Ministry of Defence increasingly uses for the approval long described as List X. Both refer to a named site cleared to hold material classified SECRET or above, and both terms remain in circulation in bids and contract documents.
No. List X approval names the site it was granted to, so a partner delivering part of the work from its own premises is not covered by the prime contractor’s approval. Ask which sites in the delivery chain hold approval and where classified material will actually be held.