Must a solicitor sign a between-the-parties bill of costs?

[TimothyP]

CPR 47 Practice Direction 5.21 provides that

The bill of costs must contain such of the certificates, the texts of which are set out in Precedent F of the Schedule of Costs Precedents annexed to this Practice Direction, as are appropriate.

[emphasis added]

Notes at the top of Precedent F itself say, among other things,

Appropriate certificates under headings (1) and (2) are required in all cases. … All certificates must be signed by the receiving party or by his solicitor. Where the bill claims costs in respect of work done by more than one firm of solicitors, certificate (1), appropriate [sic] completed, should be signed on behalf of each firm.

[emphasis added]

Certificate (1) is entitled “Certificate as to Accuracy”. The third of its three optional clauses says

… the costs claimed herein do not exceed the costs which the receiving party is required to pay me/my firm.

[emphasis added]

If a between-the-parties bill of costs includes a claim for costs that the receiving party has already paid in full to their (current or former) solicitor, is it “appropriate” for the solicitor to sign such a certificate?

Is there any decided authority?

[dls]

The sections you quote do suggest 'all bills' , but teh signature may be by the solicitor or the party.