Acas early conciliation before a tribunal claim about an AI decision

Whether the complaint is a dismissal based on a productivity score, a pay deduction made by payroll software or a detriment after questioning a monitoring tool, most employment tribunal claims in Great Britain cannot start until the claimant has contacted Acas. This step, early conciliation, is set out in section 18A of the Employment Tribunals Act 1996 and the Early Conciliation Rules of Procedure. It also affects the time limit, which is where people most often go wrong.

The short answer: before presenting a claim covered by the requirement, the prospective claimant must give Acas the prescribed information, by the online form, by post or by phone (s18A(1); rules 1 to 3). A conciliation officer then tries to promote a settlement for up to 12 weeks (rule 6). If no settlement is reached, Acas issues a certificate, and the claim cannot be presented without it (s18A(4) and (8)). For claims under the Employment Rights Act 1996, the time limit is extended to allow for this (s207B).

Starting early conciliation

Before a person presents an application to institute relevant proceedings about any matter, they must provide Acas with prescribed information about that matter, in the prescribed manner (Employment Tribunals Act 1996, s18A(1)). The rules say how: either present a completed early conciliation form, using the online form on the Acas website or by post, or telephone Acas (Early Conciliation Rules, rules 1 to 3). The form needs only the prospective claimant's name and address and the prospective respondent's name and address (rule 2(2)). More than one prospective respondent can be named (rule 4).

Acas must make reasonable attempts to contact the prospective claimant, and, if the claimant consents, the prospective respondent. If it cannot make contact with either, it must conclude that settlement is not possible (rule 5).

The conciliation period

For up to 12 weeks from the date Acas receives the form, or the date of the phone call, the conciliation officer must try to promote a settlement (rule 6(1)). The period was six weeks; 12 weeks applies where the form was presented or the call made on or after 1 December 2025 (SI 2025/1153, regs 2 and 3). The officer can keep trying to promote a settlement after the period ends (s18A(5)). Where the claim would be one of unfair dismissal, the officer may in particular seek to promote reinstatement or re-engagement, or agreement on compensation (s18A(9)).

The certificate

If the officer concludes during the period that a settlement of the dispute, or part of it, is not possible, or the period ends without a settlement, Acas must issue an early conciliation certificate (rule 7). It shows the parties' names and addresses, the date Acas received the form or call, a unique reference number and the date of issue (rule 8). It is sent by email if an email address was given, otherwise by post, and is treated as received on the day an email is sent or the day a letter would be delivered in the ordinary course of post (rule 9). A person subject to the requirement may not present a claim without a certificate (s18A(8)).

Exemptions

Early conciliation is not needed in some prescribed cases, including where another claimant has complied and the claim is on the same claim form, where the respondent has already contacted Acas about the dispute, and where an unfair dismissal claim is accompanied by an application for interim relief (Early Conciliation Regulations 2014, reg 3(1)).

How it affects the time limit

For time limits in the Employment Rights Act 1996 to which section 207B applies, the period from the day after the claimant contacts Acas (Day A) to the day the certificate is received or treated as received (Day B) is not counted (s207B(2) and (3)). If the time limit would otherwise expire between Day A and one month after Day B, it expires instead at the end of that month (s207B(4)). Where a tribunal can extend a time limit, it can extend the limit as extended by this section (s207B(5)). Other legislation has its own provisions, so check the rules for the specific claim.

The extension is worked out from the date of first contact with Acas and the date the certificate is received, so keep a record of both. For the time limit for an unfair dismissal complaint, see unfair dismissal when AI data is behind the decision.

Settling through Acas

An agreement reached with the help of an Acas conciliation officer is one of the exceptions to the rule that a contract cannot exclude statutory employment rights. The other main route is a settlement agreement with independent advice; see settlement agreements when AI changes or ends a job.

Practical steps

• Workers and employees: note the date of the decision you want to challenge, work out the time limit, and contact Acas well before it ends. Keep the Acas reference, the date of first contact and the certificate. If the dispute is about a score, flag or automated pay decision, set out briefly what the system did and what you want.
• Employers: respond when Acas makes contact. Conciliation is a chance to look again at the decision, the data behind it and whether a human reviewed it, before a claim is issued.

These provisions extend to England, Wales and Scotland. This page is general information on the law in Great Britain as at 1 November 2026, not legal advice.