When must a defendant file an acknowledgment of service?

The ordinary acknowledgment deadline is 14 days after service of the claim form. If the claim form states that particulars of claim will follow, CPR 10.3(1)(a) instead uses 14 days after service of those particulars. Select that basis before calculating. Different service orders and service outside the jurisdiction can set another period.

Responsible actor. The defendant filing an acknowledgment of service.

Read the claim form to determine whether it states that particulars will follow.

For the claim-form branch, enter the completed CPR 7.5(1) step. The calculator derives CPR 6.14 service first.

For the later-particulars branch, enter an independently established service date or derive it using the valid CPR 6.26 method.

Ordinary Part 10 acknowledgment in England and Wales. The later-particulars branch requires a claim form stating that particulars will follow. A later document alone does not establish that branch. Part 8 modifications, jurisdiction challenges, overseas service and different orders 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. Select whether the claim form states that particulars will follow.
2. Establish or derive the legally effective service event.
3. Exclude that event and count 14 calendar days.
4. For filing, check the final day against the applicable court-office calendar and order.

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. The claim form does not state that particulars will follow. The valid October 20 step gives October 22 deemed service, then 14 calendar days.

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

Service outside the jurisdiction

CPR 10.3(2) preserves Rules 6.35, 6.12(3) and 6.37(5). Do not use the ordinary domestic period for a different overseas or ordered response timetable.

Part 8 and jurisdiction

Part 8 modifies acknowledgment requirements. A jurisdiction challenge has a separate Rule 11 procedure. Selecting an acknowledgment option does not determine either question.

Contents and completion

CPR 10.5 requires the relevant form, signature, address for service and defendant identification. Preserve completed court filing, not merely a form saved or posted.

• Ordinary Part 10 acknowledgment in England and Wales. The later-particulars branch requires a claim form stating that particulars will follow. A later document alone does not establish that branch. Part 8 modifications, jurisdiction challenges, overseas service and different orders 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 claim form and read its particulars-to-follow statement.
• Establish the applicable service event and valid method.
• Read any service or response order and check Part 8 or overseas scope.
• Complete the relevant acknowledgment form and required identification.
• Use the proper court filing route and preserve confirmation.
• Track the separate defence and any jurisdiction-challenge duties.
• 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.