Временное удостоверение нужно в случае если водительское удостоверение переоформляют.

In the present tense, Russian normally omits the verb to be. So English is needed is often just expressed by the predicate itself.

Here, нужно means needed / necessary and matches удостоверение, which is neuter singular.

Compare:

• паспорт нужен — a passport is needed
• справка нужна — a certificate is needed
• удостоверение нужно — an ID/document is needed
• документы нужны — documents are needed

So Временное удостоверение нужно... is literally something like A temporary certificate/document [is] needed...

Because they are adjectives agreeing with удостоверение.

Удостоверение is:

• neuter
• singular
• here in nominative/accusative form

So the adjectives also take neuter singular nominative/accusative endings:

• временное удостоверение
• водительское удостоверение

This is standard adjective-noun agreement in Russian.

Удостоверение is a formal, official word meaning something like certificate, ID, or license document, depending on context.

So:

• водительское удостоверение = the official term for driver’s license
• права = the everyday spoken word people often use instead

This sentence sounds bureaucratic or administrative, so водительское удостоверение is the natural choice.

Because the sentence is talking about two different documents:

• временное удостоверение — the temporary document
• водительское удостоверение — the driver’s license

Official Russian often repeats the full legal term instead of replacing it with a pronoun, because that makes the statement more precise and less ambiguous.

В случае если is a more formal way to say if or in the event that.

So:

• если = if
• в случае если = in the event that / if

Using в случае если gives the sentence a more official, bureaucratic tone. In everyday speech, plain если would usually be more natural.

In careful writing, many people would write:

Временное удостоверение нужно в случае, если водительское удостоверение переоформляют.

So for a learner, в случае, если is the safest version to write.

You may also see variation in formal texts, but the version with the comma is very common and stylistically safe.

This is a very common Russian pattern: the 3rd person plural is used with no stated subject to mean they in a general, unspecified sense.

So переоформляют here means something like:

• they are reissuing it
• they are processing it again
• the authorities are redoing the paperwork

English often prefers a passive here: when the driver’s license is being reissued/reprocessed. Russian often uses this subjectless plural instead.

It is actually functioning as the direct object of переоформляют, so grammatically it is in the accusative case.

But there is an important point: for many neuter inanimate nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: водительское удостоверение
• accusative: водительское удостоверение

The case has changed in function, but not in visible form.

The verb comes from переоформлять / переоформить.

• оформить = to issue, process, formalize paperwork
• переоформить = to reissue, renew, re-register, redo the paperwork

The prefix пере- adds the idea of doing it again or anew.

The form переоформляют is imperfective, which fits a general rule or ongoing administrative process: when the license is being reissued / in cases where it is being reprocessed.

A perfective form such as переоформят would sound more like a single completed future action.

Yes. Russian word order is flexible.

For example, you could also say:

В случае, если водительское удостоверение переоформляют, нужно временное удостоверение.

Both versions are grammatical. The original sentence starts with Временное удостоверение, which puts the focus first on what is needed. That word order sounds very typical of official instructions or regulations.