Leaving your job with TRC

Hi and welcome to the forum.

For sure ..
Your WP will be terminated ASAP. Otherwise the school will have to continue to file your tax returns.
Assuming your TRC is connected to your WP, that too will be revoked because TRC is sponsored by your employer.
If the school paid for your WP and TRC you will be asked to pay back. 
They can withhold your last month's salary and other compensations for breach of contract.

Apart from that ...
I don't think Vietnam has a blacklist of rogue employees. In some other countries they have.
However, if they want they can report your PP no. to the labour department so later you may find it difficult to get another WP.

Unless there's a heavy financial loss due to contract violation, usually these schools won't go that far.

That's what I can think of at the moment.

I suggest, give them a month's notice (if possible). That's the norm.

Good luck!

Most of the time the schools are too lazy to do anything about the TRC.

In case a foreigner holds a temporary residence card that remains valid but requests the termination of his labor contract, or does not wish to have his labor contract extended upon its expiration, his employer must work with the Immigration Management Office of the Police Department of the province or city where the employer is based to return the temporary residence card, revoke the old visa and carry out procedures for grant of a new visa for the exit of the foreigner.- (VLLF)