When must a defendant file a defence under CPR 15.4?

A defence is ordinarily due 14 days after service of the particulars of claim, or 28 days after that service if the defendant files an acknowledgment of service. CPR 15.5 allows the claimant and defendant to agree up to 28 additional days. The defendant must notify the court in writing. Different rules and orders can change this timetable.

Responsible actor. The defendant filing a defence and serving a copy on every other party.

Identify the particulars of claim, including whether they were included with the claim form or served later.

Establish legally effective service under the applicable rule, method, permitted address and order.

Confirm whether an acknowledgment was filed. Preserve any agreement and the written notice to court under Rule 15.5.

Ordinary Part 15 defence after valid service of particulars. Enter a known service date or derive it from a valid CPR 6.26 method. Select a filed acknowledgment and agreed extension only when those facts exist. Part 8, overseas service, jurisdiction challenges and motion-altered timetables need separate review. The bundled service calendar assumes service in England and Wales. CPR 6.2 uses the bank holidays of the UK part where service takes place; Scotland and Northern Ireland require separate calendars.

1. Establish service of the particulars of claim.
2. Choose 14 days without a filed acknowledgment or 28 days with one.
3. Add only the actual agreed extension, at most 28 days under Rule 15.5.
4. Exclude the service day, count calendar days and check final-day court-office closure.

Exclude the established trigger day under CPR 2.8. For a period exceeding five days, count every following calendar day, including intermediate weekends and holidays. The final day counts for a within-days deadline. Apply court-office closure treatment only to an act at that office.

For an act at the court office, CPR 2.8(5) permits completion on the next day the office is open when the final day is closed. Apply the ordinary PD 2A calendar, including its one further Christmas closure, rather than treating the entire Christmas vacation as closed. A specific order or additional directed closure needs separate review.

The calculator covers complete trigger, deemed-service and result dates in 2026 and 2027. Check the actual office, filing channel, order and any additional directed closure. PD 2A closes the ordinary court office on December 24 in both years, but that office closure does not make the day a non-business day for service. Historical editions, later calendars, specialized pilots and online procedures require separate review.

Fictitious example

Fictitious established facts. Particulars are served October 20. No acknowledgment was filed and no extension is agreed.

Fictitious established facts. The calculator does not establish valid service, applicability, a filed acknowledgment, an agreed extension, court permission or actual office access.

Exceptions in the rule

CPR 15.4(2) preserves Rules 3.4(7), 6.12(3), 6.35, 11 and 24.4(4). Those situations cannot be inferred from the ordinary inputs.

Agreement and written notification

An extension under Rule 15.5 requires agreement between claimant and defendant. The defendant must notify the court in writing. A request or unilateral proposal is not an agreement.

Different procedure and service

Part 15 does not apply to Part 8 claims. Rule 15.6 separately requires service of the defence on every other party. A filing date does not prove service.

• Ordinary Part 15 defence after valid service of particulars. Enter a known service date or derive it from a valid CPR 6.26 method. Select a filed acknowledgment and agreed extension only when those facts exist. Part 8, overseas service, jurisdiction challenges and motion-altered timetables need separate review. The bundled service calendar assumes service in England and Wales. CPR 6.2 uses the bank holidays of the UK part where service takes place; Scotland and Northern Ireland require separate calendars.
• The calculator covers complete trigger, deemed-service and result dates in 2026 and 2027. Check the actual office, filing channel, order and any additional directed closure. PD 2A closes the ordinary court office on December 24 in both years, but that office closure does not make the day a non-business day for service. Historical editions, later calendars, specialized pilots and online procedures require separate review.

• Preserve the actual particulars and proof of legally effective service.
• Check whether a filed acknowledgment selects the 28-day branch.
• Read orders and the exceptions listed in CPR 15.4(2).
• Retain the claimant-defendant extension agreement and actual number of extra days.
• Notify the court in writing where Rule 15.5 applies.
• File the completed defence through the proper court route.
• Serve every other party and preserve both filing and service evidence.
• Filing means delivery to the court office under CPR 2.3. Confirm the actual court, authorized electronic or paper route, applicable time zone and receipt. CPR 5.5 and the relevant practice direction govern electronic filing. This page assumes no universal midnight or 4:30 p.m. filing cutoff. Preserve filing confirmation and complete any separate service duty.