Part 36 relevant period calculator

When is a Part 36 offer deemed served, and when does the 21-day relevant period end? Enter how and when the offer was sent. Business days use the official England & Wales bank holidays.

Date sentMethod of serviceSent after 4.30pm? Yes, after 4.30pmTrial date (optional)Adds a warning if the offer is made less than 21 days before trial.

Bank holidays could not be loaded — weekends only are excluded. Check the result against the calendar.

Deemed served: Mon, 19 October 2026

Relevant period ends Mon, 9 November 2026

CPR 6.26: email — that day if sent on a business day before 4.30pm, otherwise the next business day. Unless the offer specifies a longer period.

Email service needs the receiving party to have indicated in writing that it accepts service by email, and the address to use (PD 6A para 4.1).

The rules applied

Deemed service of documents other than a claim form: CPR 6.26. A "business day" excludes weekends and bank holidays (CPR 6.2(b)).
The relevant period is not less than 21 days: CPR 36.3(g), 36.5(1)(c), counted in clear days (CPR 2.8): service on 1 March gives a relevant period ending on 22 March.
Acceptance after the relevant period carries costs consequences: CPR 36.13(4)–(5).

Weigh the offer, not just the dates

Counsel AI's Part 36 evaluation checks the offer's validity against r.36.5, sets out the costs consequences either way, and gives a reasoned accept / reject / counter recommendation — cited to the rule.

Evaluate an offer Free document check

A calculation aid, not legal advice. It applies the rules cited above to the dates you enter; it cannot see facts that change them. Check the result before relying on it. Nothing you enter is stored.