Auf der Gehaltsabrechnung fehlt der Sozialversicherungsbeitrag.

German often uses auf with documents, lists, screens, and pages when something appears on them.

So:

• auf der Gehaltsabrechnung = on the payslip / on the salary statement
• auf der Liste = on the list
• auf der Rechnung = on the invoice

Using in would suggest something more like inside the document in a broader sense, but for entries printed or shown on a document, auf is the normal choice.

Also, auf here takes the dative because it describes a location, not movement:

• auf der Gehaltsabrechnung = location
• compare movement: auf die Gehaltsabrechnung schreiben = write onto the payslip

Because auf is followed by the dative here, and Gehaltsabrechnung is feminine: die Gehaltsabrechnung.

So the dative singular is:

• nominative: die Gehaltsabrechnung
• dative: der Gehaltsabrechnung

That is why you get auf der Gehaltsabrechnung.

fehlen means to be missing or to be absent.

In this sentence:

• Auf der Gehaltsabrechnung fehlt der Sozialversicherungsbeitrag.
• literally: On the payslip, the social insurance contribution is missing.

This is slightly different from English to miss, because German fehlen usually describes the thing that is absent, not the person who wants it.

For example:

• Der Schlüssel fehlt. = The key is missing.
• Mir fehlt der Schlüssel. = I’m missing the key / The key is missing for me.

Because der Sozialversicherungsbeitrag is the subject of fehlt.

A very common learner mistake is to assume the missing thing is an object, but with fehlen, the missing thing is normally the subject.

So in:

• Auf der Gehaltsabrechnung fehlt der Sozialversicherungsbeitrag.

the structure is:

• Auf der Gehaltsabrechnung = adverbial phrase
• fehlt = verb
• der Sozialversicherungsbeitrag = subject in the nominative

You can see this more clearly if you reorder it:

• Der Sozialversicherungsbeitrag fehlt auf der Gehaltsabrechnung.

Now it is obvious that der Sozialversicherungsbeitrag is the subject.

Because the subject is singular:

• der Sozialversicherungsbeitrag = the social insurance contribution

Since that noun is singular, the verb must also be singular:

• fehlt

If the subject were plural, the verb would be plural too:

• Auf der Gehaltsabrechnung fehlen die Sozialversicherungsbeiträge.
• The social insurance contributions are missing from the payslip.

German often moves a phrase to the front for emphasis or to set the scene.

The normal rule is: the conjugated verb must still stay in position 2.

So:

• Auf der Gehaltsabrechnung = position 1
• fehlt = position 2
• der Sozialversicherungsbeitrag = later in the sentence

A more neutral order would be:

• Der Sozialversicherungsbeitrag fehlt auf der Gehaltsabrechnung.

Both are correct. Starting with Auf der Gehaltsabrechnung puts the focus on where the problem is.

Yes, absolutely.

Both are grammatical:

• Auf der Gehaltsabrechnung fehlt der Sozialversicherungsbeitrag.
• Der Sozialversicherungsbeitrag fehlt auf der Gehaltsabrechnung.

The difference is mostly emphasis:

• Auf der Gehaltsabrechnung ... emphasizes the document first.
• Der Sozialversicherungsbeitrag ... emphasizes the missing item first.

Because German does not need a dummy subject here.

English often uses it in some structures, but German can simply put the real subject in the sentence and move other elements to the front.

So German says:

• Auf der Gehaltsabrechnung fehlt der Sozialversicherungsbeitrag.

not:

• Es fehlt der Sozialversicherungsbeitrag auf der Gehaltsabrechnung as the default version.

You can sometimes use es fehlt ..., but it changes the structure and emphasis:

• Es fehlt der Sozialversicherungsbeitrag auf der Gehaltsabrechnung.

That is possible, but less natural as a neutral statement in this context.

It is a compound noun:

• Sozialversicherung = social insurance
• Beitrag = contribution / payment

Together:

• Sozialversicherungsbeitrag = social insurance contribution

The gender of a German compound noun is determined by the last part.
Here, the last part is Beitrag, which is masculine:

• der Beitrag

So the whole compound is also masculine:

• der Sozialversicherungsbeitrag

This is a very useful rule for German compounds.

Yes, Lohnabrechnung is also possible, depending on context.

Very roughly:

• Gehalt often refers to a regular salary, especially monthly salaried pay
• Lohn often refers more traditionally to wages, especially hourly or manual work

And:

• Gehaltsabrechnung = salary statement / payslip
• Lohnabrechnung = wage statement / payroll statement / payslip

In everyday use, both may be understood as a payslip, but Gehaltsabrechnung is very common in office and salaried contexts.

Yes. In this sentence, the singular suggests one contribution item or one category entry that should appear on the payslip but does not.

German often uses the singular for a category when talking about one line item or one expected element:

• der Sozialversicherungsbeitrag fehlt = the social insurance contribution entry is missing

If several separate items were missing, you might use the plural:

• die Sozialversicherungsbeiträge fehlen

Yes, but in German the person is usually in the dative, and the missing thing is still the subject.

Examples:

• Mir fehlt der Sozialversicherungsbeitrag. = I’m missing the social insurance contribution / The social insurance contribution is missing for me.

• Dem Mitarbeiter fehlt die aktuelle Gehaltsabrechnung. = The employee is missing the current payslip.

So the pattern is often:

• Someone in dative + fehlt + thing in nominative

In your sentence, the dative person is simply not mentioned.

It sounds neutral to formal, which fits workplace, accounting, HR, or administrative language.

Words like:

• Gehaltsabrechnung
• Sozialversicherungsbeitrag

belong to standard professional vocabulary rather than casual conversation.

In more everyday speech, someone might say something simpler like:

• Der Sozialversicherungsbeitrag steht nicht auf der Abrechnung.
• The social insurance contribution isn’t on the payslip.

But your original sentence is completely natural and appropriate, especially in business or official contexts.