36.12—(1) A defendant may accept a Part 36 offer made not less than 21 days before the start of the trial without needing the court’s permission if he gives the claimant written notice of acceptance not later than 21 days after the offer was made.
(Rule 36.14 sets out the costs consequences of accepting a claimant’s offer without needing the permission of the court)
(2) If—
(a)a claimant’s Part 36 offer is made less than 21 days before the start of the trial; or
(b)the defendant does not accept it within the period specified in paragraph (1)—
(i)if the parties agree the liability for costs, the defendant may accept the offer without needing the permission of the court;
(ii)if the parties do not agree the liability for costs the defendant may only accept the offer with the permission of the court.
(3) Where the permission of the court is needed under paragraph (2) the court will, if it gives permission, make an order as to costs.