What is deemed service under the CPR?

Litigation deadlines are counted in days, so the law cannot afford arguments about when an envelope was opened. Deemed service removes the argument: the rules fix a date, and that date is the fact, even where the document demonstrably arrived earlier or later.

The two regimes

Claim forms have their own rule, CPR 6.14: whatever the method, the claim form is deemed served on the second business day after the relevant step, posting, delivering, personal service, electronic transmission, is completed. Every other document follows the method by method table in CPR 6.26: first class post or DX, the second day after posting provided it is a business day, otherwise the next business day; delivering to or leaving at a permitted address, personal service, and fax or email, that day if done before 4.30pm on a business day, otherwise the next business day. Business days exclude weekends, bank holidays, Good Friday and Christmas Day.

Why the fiction is strict

The deemed date is generally not rebuttable: a defendant cannot shorten a claimant's compliance by proving they read an email instantly, and a claimant cannot extend time by proving the post was slow. That strictness is the feature. Every downstream deadline, acknowledgment of service, defence, compliance with an order, is calculated from a date both sides can compute from a calendar, which is exactly what makes the system administrable.

Where practitioners get caught

Three recurring traps: serving late on a Friday and losing the weekend to the next business day rule; forgetting that the claim form regime differs from the general table; and confusing the date of the physical act with the deemed date when counting towards a limitation or validity deadline. When the timeline is tight, the calculation should run backwards from the deadline through the deemed service rules to the last safe day to serve, and the method chosen accordingly, with personal service the fastest certainty available.