Le compte bancaire est à découvert et sans provision.

Le compte bancaire means the bank account specifically.

French often adds bancaire to make it clear that the account is a financial/bank account, not some other kind of account such as:

• un compte utilisateur = a user account
• un compte rendu = a report
• un compte in some contexts = an account, bill, tally, etc.

In real life, French speakers may also simply say le compte if the context already makes it obvious they mean a bank account.

À découvert is a fixed expression meaning overdrawn.

So:

• un compte est à découvert = an account is overdrawn

Literally, découvert can suggest something like uncovered or exposed, but in banking this expression has the specific meaning in overdraft / overdrawn.

This is a standard idiomatic phrase, so it is best learned as a whole:

• être à découvert = to be overdrawn

Because à découvert is the established idiom for this banking meaning.

Compare:

• Le compte est à découvert = The account is overdrawn
• Le compte est découvert would sound odd here and would not normally be used for banking

French often uses fixed prepositional expressions after être, and this is one of them:

• être à découvert
• être à jour = to be up to date
• être à l’abri = to be sheltered/safe

So the à is part of the expression, not something optional.

Sans provision means without sufficient funds.

In banking French, provision refers to the money available in the account to cover a payment. So if an account or a cheque is sans provision, there is not enough money in the account.

Common related use:

• un chèque sans provision = a bad cheque / a cheque backed by insufficient funds

In your sentence, sans provision reinforces the idea that the account has no money available to cover payments.

Because both parts are idiomatic expressions:

• à découvert
• sans provision

These are set phrases, so you do not normally insert an article:

• not à un découvert
• not sans une provision

This is similar to how English fixed expressions often do not behave literally word-for-word.

They are very close, but not quite identical in nuance.

• à découvert focuses on the account being in overdraft / below zero
• sans provision focuses on the fact that there are no funds available to cover a payment

In many contexts, they overlap a lot, and here they work together to emphasize the bad financial situation of the account.

So the sentence is a bit stronger than using only one of them.

French, like English, often avoids repeating the verb when the subject is the same.

So:

• Le compte bancaire est à découvert et sans provision

means:

• The bank account is overdrawn and without funds

This is completely natural. Repeating est would be grammatically possible, but less elegant:

• Le compte bancaire est à découvert et est sans provision

A simple pronunciation guide is:

luh kont bon-kair ay ta day-koo-vair ay sahn pro-vee-zyohn

A few useful points:

• compte: the p is silent
• bancaire: sounds roughly like bon-kair
• est à often links smoothly in speech
• sans has a nasal vowel; the n is not fully pronounced like English n
• provision ends with the -sion sound, like zyohn

Depending on accent and speed, native pronunciation will vary a bit.

It sounds fairly formal or administrative, especially because of sans provision.

• à découvert is common in everyday French
• sans provision sounds more banking-related, legal, or official

A more everyday way to talk about the situation might be:

• Le compte est dans le rouge = The account is in the red
• Il n’y a plus d’argent sur le compte = There’s no more money in the account

So your sentence is natural, but it has a somewhat official/banking tone.

Yes.

As a noun, un découvert means an overdraft.

For example:

• avoir un découvert = to have an overdraft
• un découvert bancaire = a bank overdraft

But in your sentence, à découvert is not a noun phrase. It is part of the expression être à découvert.

So compare:

• Le compte est à découvert. = The account is overdrawn.
• Le découvert est important. = The overdraft is significant.

Yes, it is understandable and natural, especially in a banking or administrative context.

That said, in ordinary conversation a speaker might more often say:

• Le compte est à découvert.
• Le compte est dans le rouge.
• Il n’y a pas assez d’argent sur le compte.

So the sentence you have is correct, but it sounds a bit more formal and emphatic than the most casual everyday phrasing.