Abban az esetben, ha változik a lakcím, visszavonjuk a parkolási engedélyt.

It means in that case or, more naturally in this sentence, in the event that.

Literally:

• eset = case
• esetben = in the case
• abban = in that

So abban az esetben, ha... is a formal way to say if...

A little, yes — but it is very normal Hungarian, especially in formal or administrative language.

• ha by itself already means if
• abban az esetben, ha is a more official, heavier version, like in the event that

So:

• Ha változik a lakcím... = simpler, more direct
• Abban az esetben, ha változik a lakcím... = more formal, bureaucratic

Because Hungarian often marks the case twice in this kind of structure: once on the demonstrative and once on the noun phrase.

So:

• abban = in that
• az esetben = in the case

This is standard Hungarian grammar. Compare:

• ebben a házban = in this house
• abban az autóban = in that car

So abban az esetben follows the same pattern.

Because Hungarian normally uses a demonstrative plus the definite article before the noun.

Pattern:

• ez a könyv = this book
• az a ház = that house
• abban az esetben = in that case

So the middle az is the article the, not an extra unnecessary word.

Both are possible, but the word order changes the feel slightly.

• ha változik a lakcím is a more neutral, event-focused way to say if the address changes
• ha a lakcím változik makes a lakcím more of a topic, as if you are specifically talking about the address rather than something else

In official writing, ha változik a lakcím sounds very natural.

Lakcím means residential address or home address, especially in an official/administrative sense.

It is not just any address in a casual sense. In Hungarian paperwork, lakcím usually means the address where a person is officially registered as living.

Hungarian often uses the definite article where English would use a possessive such as your.

So in context:

• a lakcím can mean the address or effectively your address
• a parkolási engedélyt can mean the parking permit or effectively your parking permit

Official Hungarian often leaves this implicit when it is obvious from context whose address or permit is meant.

This is an important distinction:

• változik = changes, undergoes change
• változtat = changes something, causes something to change

Here the subject is a lakcím, and the meaning is the address changes, so Hungarian uses változik.

Compare:

• A lakcím változik. = The address changes.
• Megváltoztatjuk a lakcímet. = We change the address.

It means we revoke, we withdraw, or we cancel in an official sense.

The dictionary form is visszavon.

Breakdown:

• vissza = back
• von = pull / draw
• visszavon = withdraw, revoke
• visszavonjuk = we revoke it

In administrative language, visszavonni egy engedélyt is the normal way to say to revoke a permit.

Because Hungarian has definite and indefinite verb conjugation.

Here the object is definite:

• a parkolási engedélyt = the parking permit

So the verb takes the definite ending:

• visszavonjuk = we revoke it / we revoke the permit

Compare:

• Visszavonunk egy engedélyt. = We revoke a permit.
  This uses the indefinite conjugation.
• Visszavonjuk az engedélyt. = We revoke the permit.
  This uses the definite conjugation.

Because engedélyt is the accusative form, marking the direct object.

• engedély = permit
• engedélyt = permit, as the thing being acted on

The accusative ending is usually -t.

So:

• a parkolási engedély = the parking permit
• a parkolási engedélyt = the parking permit, as the object of visszavonjuk

Parkolási means related to parking or for parking.

It comes from:

• parkol = to park
• parkolás = parking
• parkolási = parking-related, for parking

So:

• parkolási engedély = parking permit

This is the normal official term.

Parkoló usually means something different, such as:

• a parking area / car park
• or something/someone that is parking, depending on context

So parkoló engedély would not be the standard expression here.

Grammatically, the verbs are in the present tense:

• változik
• visszavonjuk

But the meaning is often future-oriented: it describes what will happen if that condition is met.

This is very normal in Hungarian. Rules, procedures, and conditional statements often use the present tense where English might use will.

So the sense is:

• If the address changes, we will revoke the parking permit.

Yes. A simpler version would be:

Ha változik a lakcím, visszavonjuk a parkolási engedélyt.

That means the same thing, but sounds less formal.

The original sentence sounds more like official policy language, which is why it uses abban az esetben, ha.