Adresseendringen er ferdig.

Because Norwegian usually forms compound nouns as one single word.

So English change of address becomes Norwegian adresseendring:

• adresse = address
• endring = change

Together:

• en adresseendring = a change of address

Then the definite ending is added:

• adresseendringen = the change of address

This “one-word compound” pattern is extremely common in Norwegian.

The -en is the definite article attached to the noun.

Compare:

• en adresseendring = a change of address
• adresseendringen = the change of address

Unlike English, Norwegian often puts the at the end of the noun instead of using a separate word.

So here:

• adresseendring = change of address
• adresseendringen = the change of address

Because in this sentence, adresseendringen works fine by itself as a definite noun.

In Norwegian, a definite noun often just takes the ending:

• Bilen er klar. = The car is ready.
• Adresseendringen er ferdig. = The change of address is finished.

You often use den + noun with definite ending when there is an adjective before the noun:

• den nye adresseendringen = the new change of address

This is called double definiteness.

So:

• adresseendringen = correct
• den adresseendringen = possible only in more special contexts, often with emphasis or contrast, not the neutral default here

Er is the present tense of å være (to be).

So the structure is:

• Adresseendringen = the change of address
• er = is
• ferdig = finished / done / complete

Literally:

• The change of address is finished.

This is a very common Norwegian pattern: subject + er + adjective

For example:

• Maten er klar. = The food is ready.
• Jobben er ferdig. = The job is finished.

Because ferdig agrees with the noun, and here the subject is singular common gender.

Norwegian predicative adjectives usually work like this:

• common gender singular: ferdig
• neuter singular: ferdig
• plural: ferdige

Examples:

• Bilen er ferdig. = The car is finished.
• Huset er ferdig. = The house is finished.
• Bilene er ferdige. = The cars are finished.

So in this sentence:

• adresseendringen is singular
• therefore ferdig is correct

A learner may expect a special neuter form like ferdigt, but that is not used in modern Norwegian Bokmål. The adjective is just ferdig in the singular.

Here, ferdig is an adjective used predicatively.

That means it comes after er and describes the subject:

• Adresseendringen er ferdig.

It means something like:

• finished
• done
• complete

In everyday Norwegian, ferdig is very common for saying that something has been completed.

Examples:

• Jeg er ferdig. = I’m finished / I’m done.
• Vi er ferdige. = We’re finished.
• Rapporten er ferdig. = The report is finished.

They are similar, but not always identical in tone or usage.

• ferdig = finished, done, ready, complete
• fullført = completed, carried through

In many situations, ferdig sounds more natural and everyday:

• Adresseendringen er ferdig.

Fullført can sound a bit more formal or official:

• Adresseendringen er fullført.

So both can work, but ferdig is often the more natural everyday choice.

Yes, it is natural.

Adresseendringen er ferdig sounds like a normal way to say that the address change process has been completed.

Depending on context, Norwegian speakers might also say:

• Adresseendringen er fullført.
• Adressen er endret. = The address has been changed.
• Vi er ferdige med adresseendringen. = We are finished with the change of address.

But the original sentence is perfectly normal.

Norwegian often expresses this idea with a simple present tense of være + adjective:

• er ferdig = is finished / is done

English often prefers:

• has been completed
• is finished

Norwegian may use either a similar passive/perfect construction or the simpler adjective structure.

Compare:

• Adresseendringen er ferdig. = The change of address is finished.
• Adresseendringen er blitt fullført. = The change of address has been completed.

The first version is shorter and more natural in everyday language.

Because this is a basic declarative main clause in Norwegian:

• Adresseendringen = subject
• er = verb
• ferdig = subject complement

So the pattern is:

Subject + verb + complement

This is the normal word order in straightforward statements.

If you move something else to the front, Norwegian still keeps the verb in second position, but in this sentence there is nothing extra before the subject, so the structure stays simple.

Usually, no—not if you mean the specific address change.

• Adresseendringen er ferdig. = The address change is finished.

Without the definite ending:

• Adresseendring er ferdig

that sounds incomplete or unnatural in ordinary Norwegian, unless it appears in a very special style such as a heading, note, or telegraphic message.

So in a normal sentence, adresseendringen is the correct form.

The main stress is usually on the first part of the compound:

• a-DRES-se-end-ring-en

In Norwegian compounds, the first element often carries the main stress, unlike English, where stress patterns can vary more.

Also remember:

• the whole thing is one word
• the ending -en is unstressed
• the noun should sound like one unit, not like three separate words

A learner should especially notice that adresseendring is treated as a single compound noun.

In Bokmål, it is most commonly treated as a common gender noun, usually with en:

• en adresseendring
• adresseendringen

Even though Norwegian historically distinguishes masculine and feminine in many cases, many Bokmål users use the en-form for a lot of nouns.

So for a learner, the safest form is:

• en adresseendring
• adresseendringen

Only the first word is capitalized here because it starts the sentence.

So:

• At the start of a sentence: Adresseendringen er ferdig.
• In the middle of a sentence: Jeg fikk beskjed om at adresseendringen er ferdig.

Norwegian capitalization is generally simpler than English: common nouns like adresseendring are not capitalized unless they begin a sentence.