Die Benutzernummer steht auf dem nicht übertragbaren Ersatzausweis.

Not literally. In this sentence, stehen auf means something like is written on, appears on, or is printed on.

So Die Benutzernummer steht auf dem ... Ersatzausweis means that the user number is shown on that document.

German often uses stehen in this way for text or information:

• Die Telefonnummer steht auf der Karte. = The phone number is on the card.
• Das Datum steht oben rechts. = The date is at the top right.

So yes, the basic verb is stehen = to stand, but here it is used idiomatically for written information.

Because auf is one of the German two-way prepositions. It can take:

• dative when it describes a location (where?)
• accusative when it describes movement toward a place (where to?)

Here, the sentence is talking about where the number already is: it is located on the replacement ID. That is a where idea, so German uses the dative:

• auf dem Ersatzausweis = on the replacement ID

Compare:

• Die Nummer steht auf dem Ausweis. = The number is on the ID. → location → dative
• Ich schreibe die Nummer auf den Ausweis. = I write the number onto the ID. → movement/direction → accusative

Because Ersatzausweis is a masculine noun: der Ersatzausweis.

When a masculine noun is in the dative singular, the definite article becomes dem:

• nominative: der Ersatzausweis
• dative: dem Ersatzausweis

So:

• auf dem Ersatzausweis

That is why you see dem and not der or den here.

Because it is an adjective describing Ersatzausweis, and it comes after the definite article dem.

The full phrase is:

• dem nicht übertragbaren Ersatzausweis

Here, Ersatzausweis is:

• masculine
• singular
• dative

After a definite article such as dem, an adjective in the dative masculine singular normally takes -en:

• dem alten Ausweis
• dem neuen Pass
• dem nicht übertragbaren Ersatzausweis

Also note that nicht itself does not change. It is an adverb modifying übertragbaren.

It means not transferable.

In this context, it usually means the document cannot be passed on, assigned, or used by another person. It is tied to one specific person and cannot legally or officially be transferred.

A native English speaker might expect something like non-transferable, and that is exactly the idea here.

You may also see unübertragbar in German. That can mean almost the same thing. Nicht übertragbar is simply the wording used in this sentence.

It is a compound noun made from:

• Ersatz = replacement, substitute
• Ausweis = ID card, identification document, pass

So Ersatzausweis means replacement ID, temporary replacement pass, or something similar, depending on the context.

German very often combines words like this into one noun.

Because German commonly forms compound nouns by joining nouns together into a single word.

Here:

• Benutzer = user
• Nummer = number

So:

• Benutzernummer = user number

This is completely normal in German. English often writes these as separate words, but German usually writes them as one word.

Also, the gender of a compound noun is determined by the last part. Since Nummer is feminine (die Nummer), the whole compound is feminine:

• die Benutzernummer

German uses definite articles more often than English does.

Here, die Benutzernummer refers to a specific item in the situation: the user number that belongs on that document. In instructions, notices, and official language, German often uses the definite article where English might say:

• User number is on the replacement ID
• The user number is on the replacement ID
• or even Your user number is on the replacement ID

German prefers:

• Die Benutzernummer ...

So the article sounds natural and normal here.

Because German main clauses normally follow the verb-second rule.

In a standard statement, the finite verb goes in the second position:

• Die Benutzernummer steht auf dem ... Ersatzausweis.

Here the first position is the subject:

• Die Benutzernummer = position 1
• steht = position 2

After that comes the rest of the sentence.

You could also move another element to the front, but the verb would still stay second:

• Auf dem nicht übertragbaren Ersatzausweis steht die Benutzernummer.

That is still correct, because steht remains in second position.

Because many masculine and neuter nouns in German do not visibly change in the dative singular. Often only the article changes.

So:

• der Ersatzausweis → nominative
• dem Ersatzausweis → dative

The noun stays the same, but the article changes from der to dem.

This is normal for many nouns:

• der Pass → dem Pass
• der Ausweis → dem Ausweis

Because they are nouns, and German capitalizes all nouns.

That is one of the most noticeable spelling rules in German. In this sentence:

• Benutzernummer is a noun
• Ersatzausweis is a noun

So both start with capital letters.

Adjectives and verbs are not capitalized here:

• steht = verb
• nicht übertragbaren = adjective phrase

Yes. That is also correct.

German word order is flexible as long as the finite verb stays in second position in a main clause.

So both of these are correct:

• Die Benutzernummer steht auf dem nicht übertragbaren Ersatzausweis.
• Auf dem nicht übertragbaren Ersatzausweis steht die Benutzernummer.

The difference is mainly emphasis:

• starting with Die Benutzernummer focuses first on the number
• starting with Auf dem nicht übertragbaren Ersatzausweis focuses first on the document/location