Tribunal claims usually have to be presented within three or six months of either employment ending or of the alleged incident r behaviour, depending on the type of claim.
You then have 28 days to lodge your response.
The tribunal can reject claims for various reasons, eg because the claim is made out of time (late) or doesn't contain enough information.
If the tribunal accepts a claim against you or your organisation, it will send you a copy of the claim form (form ET1(NI)) usually within three days of receipt. It will also send you a blank response form (form ET3(NI)).
You can still settle the matter without the need for a tribunal hearing, eg by reaching an agreement with the claimant through conciliation, or by mutually agreeing that the matter is dealt with via the Labour Relations Agency (LRA) Arbitration Scheme.
However, should a hearing still be necessary, you should ensure that you are prepared for it, by organising the documents you need and summoning any witnesses.
The Office of the Industrial Tribunals and the Fair Employment Tribunal (OITFET) is responsible for the administration and organisation of the tribunals.