Samordnet registermelding er ferdig, bortsett fra at informasjonen om næringsvirksomheten mangler.

Because it is being used as an indefinite singular noun phrase: Samordnet registermelding = a coordinated register notification/form.

In Norwegian, you often do not need an article in the same places where English would use a or the, especially in headings, labels, or slightly formal administrative language. Here it functions as the subject of the sentence, and the style is typical of official Norwegian.

Also, this is a noun phrase made up of:

• samordnet = coordinated / joint
• registermelding = register notification / registration form

So the sentence starts with the thing being talked about: Samordnet registermelding.

Because registermelding is singular.

In Norwegian, adjectives and adjective-like words can agree with the noun. Here:

• en registermelding → singular common gender
• therefore: er ferdig

Compare:

• Meldingen er ferdig = The form is finished
• Meldingene er ferdige = The forms are finished

So ferdig is the correct singular form here.

Bortsett fra at means except that or apart from the fact that.

It introduces an exception to the main statement:

• Samordnet registermelding er ferdig = The form is complete
• bortsett fra at ... = except that ...

So the sentence means that everything is complete, with one remaining problem.

You can think of it as:

• bortsett fra = except for / apart from
• at = that

Because it means the information, not just information in a general sense.

In Norwegian:

• informasjon = information
• informasjonen = the information

The definite form is used because the sentence refers to specific information that is expected in this context, namely the information about the business activity.

So:

• informasjon mangler would sound more general
• informasjonen mangler means a specific set of information is missing

Yes. Here om means about, regarding, or concerning.

So:

• informasjonen om næringsvirksomheten = the information about the business activity

This is a very common use of om in Norwegian:

• en bok om Norge = a book about Norway
• informasjon om skatt = information about tax
• spørsmål om arbeid = questions about work

Because it refers to the specific business activity connected to this registration, not business activity in general.

Breakdown:

• næringsvirksomhet = business activity / commercial activity
• næringsvirksomheten = the business activity

In this administrative context, the sentence is talking about the particular business activity that the form is supposed to describe. That is why the definite form sounds natural.

It is a compound noun:

• næring = trade, industry, business
• virksomhet = activity, operation, enterprise

Together, næringsvirksomhet means something like business activity, commercial activity, or business operations.

This kind of long compound noun is very common in Norwegian. English often uses several separate words where Norwegian prefers one compound word.

Because Norwegian often uses the present tense to describe a current state or status.

So:

• mangler = is missing / is lacking

The idea is not really about an action happening right now in a dramatic sense. It is simply stating the current situation: the information is not there.

This is very natural in Norwegian administrative language:

• Dokumentasjon mangler = Documentation is missing
• Signaturen mangler = The signature is missing

Because at introduces a subordinate clause, and subordinate clauses do not use the normal main-clause verb-second pattern in the same way.

Main clause:

• Informasjonen mangler.

After at:

• ... at informasjonen mangler

So the structure is:

• at
  • subject + verb

If there were a sentence adverb like ikke, you would clearly see the subordinate-clause pattern:

• ... at informasjonen ikke mangler = ... that the information is not missing

That placement of ikke before the verb is a classic sign of a subordinate clause in Norwegian.

It can suggest all three, depending on context.

In this sentence, ferdig is best understood as complete or finished. Since the sentence then adds an exception, the meaning is roughly:

• The coordinated registration form is complete, except that information about the business activity is missing.

In everyday Norwegian, ferdig is very flexible:

• Jeg er ferdig. = I’m finished / I’m done.
• Maten er ferdig. = The food is ready.
• Arbeidet er ferdig. = The work is finished / complete.

So the exact English translation depends on context.