You must start your unfair dismissal claim within three months less one day from the date your employment was terminated.
For example, if your employment ended on 3 October, then you must start your claim by 2 January.
You must contact ACAS to go through its Early Conciliation process before you can make a claim through the Employment Tribunal. Again you must do this within three months, less one day from the date your employment ended.
ACAS Early Conciliation is an attempt to settle your unfair dismissal claim without it needing to go to the Tribunal. You don’t need to communicate with your employer directly through this process, as ACAS will act as a go between.
While the ACAS process is going on, the time limit for making a claim through the Tribunal is paused.
If ACAS Early Conciliation is unsuccessful, then you will be issued with a certificate. This will then allow you to claim through the Employment Tribunal. Generally you’ll have at least a month to make your unfair dismissal claim once you get your certificate.