(1) A party may amend their statement of case, including by removing, adding or substituting a party, at any time before it has been served on any other party.
(2) If his statement of case has been served, a party may amend it only –
(a) with the written consent of all the other parties; or
(b) with the permission of the court.
(3) If a statement of case has been served, an application to amend it by removing, adding or substituting a party must be made in accordance with rule 19.4.
(4) A party who files a notice under Part 38 discontinuing all or part of a claim may amend their statement of case without the court’s permission to give effect to the discontinuance.
(Part 22 requires amendments to a statement of case to be verified by a statement of truth unless the court orders otherwise)
17.2
(1) If a party has amended their statement of case where permission of the court was not required, the court may disallow the amendment.
(2) A party may apply to the court for an order under paragraph (1) within 14 days of service of a copy of the amended statement of case on them.
17.3
(1) Where the court gives permission for a party to amend their statement of case, it may give directions as to –
(a) amendments to be made to any other statement of case; and
(b) service of any amended statement of case.
(2) The power of the court to give permission under this rule is subject to –
(a) rule 19.2 (change of parties – general);
(b) rule 19.6 (special provisions about adding or substituting parties after the end of a relevant limitation period (GL) ); and
(c) rule 17.4 (amendments of statement of case after the end of a relevant limitation period).
17.4
(1) This rule applies where –
(a) a party applies to amend their statement of case in one of the ways mentioned in this rule; and
(b) a period of limitation has expired under –
(i) the Limitation Act 1980 1 ;
(ii) the Foreign Limitation Periods Act 1984 2 ; or
(iii) any other enactment which allows such an amendment, or under which such an amendment is allowed.
(2) The court may allow an amendment whose effect will be to add or substitute a new claim, but only if the new claim arises out of the same facts or substantially the same facts as are already in issue on as a claim in respect of which the party applying for permission has already claimed a remedy in the proceedings.
(3) The court may allow an amendment to correct a mistake as to the name of a party, but only where the mistake was genuine and not one which would cause reasonable doubt as to the identity of the party in question.
(4) The court may allow an amendment to alter the capacity in which a party claims if the new capacity is one which that party had when the proceedings started or has since acquired.
(Rule 19.6 specifies the circumstances in which the court may allow a new party to be added or substituted after the end of a relevant limitation period (GL) )