Equipment in the Swedish Armed Forces is identified by M-numbers (M-nummer) – designations in the armed forces’ materiel catalogue. An M-number means the item is a defined, approved article in the defence logistics system: specified, traceable and orderable as exactly that item.
FMV – Försvarets materielverk, the Swedish Defence Materiel Administration – is the agency that procures and manages materiel for the Armed Forces, sets requirements and approves suppliers.
What an M-number actually guarantees
It is easy to read an M-number as a quality mark. It is more specific and more useful than that.
The number designates one article in one configuration. Not a product family, not a model range – a specific item as it was evaluated.
The article exists in the logistics system with a defined supply chain behind it. Where it came from and who may supply it are recorded rather than assumed.
Any unit can order the same verified article and receive the same thing. That sounds administrative until you consider the alternative: units independently sourcing equivalent-looking equipment, and a fleet that is not actually uniform.
Articles in the system are expected to be supported, repairable and deliverable over defence timescales – decades, not consumer product cycles.
What it is not
An M-number is not a TEMPEST certificate, and the two are regularly confused in requirement specifications.
A TEMPEST certificate is a laboratory’s verdict: this device, in this configuration, keeps its emissions below the limit for a given level. It is a technical measurement made by an accredited third party.
An M-number is the customer’s decision: this article may be used in our systems. It follows an assessment that may take certification into account along with much else – supply chain, supportability, interoperability, fitness for the intended use.
Neither replaces the other. Equipment can hold a TEMPEST certificate without an M-number, which is the normal case for products sold outside the Swedish Armed Forces. Equipment can hold an M-number without being TEMPEST-certified, because most materiel does not process classified information. For a classified workplace in Swedish defence, both are typically required, and they are required for different reasons.
Why configuration control matters here
The connection between the two becomes concrete when something changes.
A TEMPEST certificate applies to a tested configuration. Swap a component and the tested configuration no longer exists. An M-number pins that same configuration in the materiel system, which means a change is not a quiet supplier decision – it is a change to a catalogued article, with a process attached.
That is not bureaucracy for its own sake. It is what prevents a certified workplace from being degraded over years by a series of individually reasonable component substitutions, each of which invalidated an approval that nobody re-checked.
In procurement
If you are buying for the Swedish Armed Forces, or for an organisation that delivers into it, state the requirement explicitly. “TEMPEST-certified” and “carries an M-number” are two separate clauses and should both appear if both are needed.
It is also worth asking suppliers early. An M-number is granted through a process involving the procuring authority; it is not something a supplier can produce on request for a product that does not have one. If a delivery depends on it, that dependency belongs at the start of the timeline. Procurement support covers how to word the requirement.
For deliveries outside Swedish defence, M-numbers are usually irrelevant and asking for them narrows the field for no benefit.
Fibersystem and the materiel system
Fibersystem is a main supplier to the Swedish Total Defence. Certified products carry M-numbers where they have been granted – visible on the relevant product pages, for example the FO USB 2.0 card modules – and we deliver under the sector’s frameworks as a SOFF member and NATO-certified TEMPEST supplier.
For units and programmes with needs outside the catalogue, custom development takes a requirement from idea to certified end product, designed and built in Stockholm. See also defence solutions.
