La comissió bancària és al contracte.

Because al is the normal contraction of a + el in Catalan.

• a + el = al
• de + el = del

So al contracte literally comes from a el contracte.
This is similar to how Spanish uses al.

A useful comparison:

• al contracte = in / at the contract
• a la clàusula = in / at the clause
  There is no contraction with la.

Comissió is a feminine noun, so it takes:

• the feminine article la
• the feminine form of the adjective: bancària

So the agreement is:

• la comissió
• comissió bancària

Many Catalan nouns ending in -ió are feminine, so this pattern is very common.

In Catalan, adjectives usually come after the noun.

So:

• comissió bancària = bank fee / banking commission

This is the normal word order.
English often puts the describing word first, but Catalan usually puts it after.

Compare:

• contracte bancari = bank contract / banking contract
• comissió bancària = bank fee

Because adjectives must agree with the noun in gender and number.

Here:

• comissió is feminine singular
• so the adjective must also be feminine singular: bancària

Compare:

• el contracte bancari = masculine singular
• la comissió bancària = feminine singular
• les comissions bancàries = feminine plural

The accent in és shows both stress and meaning.

• és = is
• es = a pronoun, like oneself / himself / herself / itself in some contexts

So the accent helps distinguish the verb from another very common word.

It is pronounced roughly like ess, with the stress on that one syllable.

This is a very common learner question.

In Catalan, both ser and estar can appear with location, but the choice depends on usage, style, and nuance. In a sentence like this, és al contracte can sound like it is in the contract / it appears in the contract / it is included in the contract.

So és here is not just physical location; it can suggest that the fee is part of what the contract says.

If you said està al contracte, many speakers would also understand it, especially in everyday speech, but és al contracte fits well when you mean something like it is stated in the contract.

Yes, in this kind of sentence it is understood that way.

Literally, a often means to, at, or in, depending on context. With documents like contracte, al contracte can mean:

• in the contract
• in the text of the contract
• included/stated in the contract

So even though English strongly prefers in, Catalan can use a + article here.

Usually it refers to a bank charge, bank fee, or bank commission.

The exact English translation depends on context:

• comissió bancària = a fee charged by a bank
• in financial English, commission may be possible
• in everyday English, bank fee is often the clearest translation

So the Catalan phrase is normal, but the best English equivalent can vary a little.

No, not in normal Catalan.

Catalan usually needs an article before a singular countable noun in a sentence like this. So:

• La comissió bancària és al contracte. = correct
• Comissió bancària és al contracte. = not natural / incorrect in standard use

If you change the meaning, you could use another determiner:

• Una comissió bancària és al contracte. = A bank fee is in the contract
• Aquesta comissió bancària és al contracte. = This bank fee is in the contract

A simple pronunciation guide is:

La comissió bancària és al contracte
luh koo-mee-see-O ban-KA-ree-uh ez uhl kon-TRAK-tuh

A few stress points:

• comissió → stress on the last syllable: -sió
• bancària → stress on -cà-
• és → one stressed syllable
• contracte → stress on trac

The written accents help you see where the stress goes in comissió, bancària, and és.

Yes. Depending on the nuance, Catalan might also use:

• La comissió bancària consta al contracte.
  = The bank fee is stated in the contract.

• La comissió bancària apareix al contracte.
  = The bank fee appears in the contract.

• La comissió bancària està inclosa al contracte.
  = The bank fee is included in the contract.

Your original sentence is understandable and simple, but these alternatives can sound a bit more precise depending on what you want to express.