Can a foreign company look up Norwegian companies without registering anything?

Yes, freely. Brønnøysund's Enhetsregisteret open data is NLOD-licensed, keyless, and free — no Norwegian presence, no account, no certificate. That covers company existence, entity type, status, roles, and VAT registration. The gate only appears when you want to authenticate as an organisation or act on one's behalf.

Which part of Altinn 3 access blocks a foreign entity first?

The organisation number underneath everything. Altinn 3's System User model has three legs — a Maskinporten client, Digdir's signed terms of use, and an Altinn System Register entry — and each one identifies your organisation by a Norwegian organisation number, directly or through the enterprise certificate that requires one. An entity with no Norwegian registration stalls before leg one.

Is a NUF enough, or does a foreign company need a subsidiary?

Brønnøysund's guidance is that a foreign business needing a Norwegian organisation number registers a NUF — a Norwegian-registered foreign business, which is a registration of your existing company, not a new legal entity. Whether a NUF or another structure fits your commercial and tax situation is professional advice; this page only states the registration fact.

Can a foreign integrator use Altinn's serviceowner APIs instead of the System User model?

No — and neither can a Norwegian one. Altinn confirmed in May 2026 that serviceowner instance scopes are reserved for public agencies. Every private integrator, regardless of country, works through the customer-delegated System User model: each customer explicitly grants rights to your registered system.

Foreign access

Yes, a foreign company can access Altinn 3 — the distance depends on reading versus acting.

Reading Norwegian registry data requires nothing at all. Acting through Altinn 3 — filing, submitting, approving — anchors on a Norwegian organisation number at every leg, and the documented bridge for a foreign business is NUF registration.

Reading: Brønnøysund without a Norwegian presence

The honest answer is one paragraph: yes, freely. Brønnøysund's Enhetsregisteret data — company existence, entity type, status, board roles, signing authority, VAT registration — is published as open data under the NLOD licence, keyless and free. No Norwegian entity, no account, no certificate. If your only need is verifying Norwegian counterparties, you already have access and nothing on this page gates you.

Acting: where each System User leg anchors

Acting on behalf of a Norwegian company runs through Altinn 3's System User model. The full three-leg mechanics live in the Altinn System Users guide — this section only maps each leg to its jurisdictional anchor, which is the part that decides how far a foreign entity gets.

Leg 1 — the Maskinporten client is bound to a virksomhetssertifikat, and both issuing CAs anchor that certificate on an entity registered in the Norwegian Enhetsregisteret — the certificate page has the sourced detail.
Leg 2 — Digdir's bruksvilkår (terms of use) are signed in Samarbeidsportalen on behalf of the registered organisation, by someone whose authority for that organisation can be verified.
Leg 3 — the Altinn System Register entry identifies the system vendor by organisation number in the 0192: namespace — the ISO 6523 code for the Norwegian Enhetsregisteret. As of July 2026, Altinn's System User documentation expresses vendor identity in that Norwegian-registry namespace.

The stall point, in other words, is not Altinn being closed to foreigners — it is that every leg resolves your identity through the Norwegian business registry. Solve the registry anchor and the legs open in order.

The NUF bridge

Brønnøysund's own guidance: “All foreign businesses in need of a Norwegian organisation number must register as a Norwegian registered foreign business (NUF).” A NUF is a registration of your existing foreign company — it yields the organisation number the certificate, portal, and register legs all reference. Whether a NUF fits your commercial and tax situation, versus any other structure, is a question for your own advisers — this page states the registration fact and stops.

One first-hand data point on how real NUFs are in Norwegian machine-readable infrastructure: NUF is a first-class entity type in Apier's own public API — a NUF resolves to a company record like any AS — but obligation verdicts for the NUF entity type are not yet published in our rulebook, so an obligations query returns the record with an explicit unpublished-template note rather than a verdict. You can check this yourself in the sandbox. The wider lesson generalises: Norwegian systems know what a NUF is, but NUF support frequently trails AS support — verify, per system, rather than assume.

The route that is closed to everyone private

A useful boundary to know before you plan an architecture: on 26 May 2026, Altinn confirmed to us that the serviceowner/instances.* scopes are reserved for public agencies. A private integrator — Norwegian or foreign — does not get the service-owner surface. The working model for everyone private is the customer-delegated System User: your system is registered, and each customer organisation explicitly grants it rights. This is not a foreign-company limitation; it is the shape of the platform.

And the limitation that catches integrators most often, quoted from our own guide: “A System User without rights authenticates but cannot act.” Registration gets you a login; only the customer's explicit delegation gets you authority. The two are checked separately — the System Users guide covers both questions.

FAQ

Can a foreign company look up Norwegian companies without registering anything?: Yes, freely. Brønnøysund's Enhetsregisteret open data is NLOD-licensed, keyless, and free — no Norwegian presence, no account, no certificate. That covers company existence, entity type, status, roles, and VAT registration. The gate only appears when you want to authenticate as an organisation or act on one's behalf.
Which part of Altinn 3 access blocks a foreign entity first?: The organisation number underneath everything. Altinn 3's System User model has three legs — a Maskinporten client, Digdir's signed terms of use, and an Altinn System Register entry — and each one identifies your organisation by a Norwegian organisation number, directly or through the enterprise certificate that requires one. An entity with no Norwegian registration stalls before leg one.
Is a NUF enough, or does a foreign company need a subsidiary?: Brønnøysund's guidance is that a foreign business needing a Norwegian organisation number registers a NUF — a Norwegian-registered foreign business, which is a registration of your existing company, not a new legal entity. Whether a NUF or another structure fits your commercial and tax situation is professional advice; this page only states the registration fact.
Can a foreign integrator use Altinn's serviceowner APIs instead of the System User model?: No — and neither can a Norwegian one. Altinn confirmed in May 2026 that serviceowner instance scopes are reserved for public agencies. Every private integrator, regardless of country, works through the customer-delegated System User model: each customer explicitly grants rights to your registered system.