I am a rotary examiner so feel that I am on slightly shaky ground with regard to fixed-wing forms.
Nothwithstanding, I believe that a form SRG 1157 may be required for a revalidation where no action is required by the CAA.
You may hear mention of the forms SRG 1119B and SRG 1119C. These appear to be required for revalidations and renewals respectively only if the examiner is unable to sign the licence revalidation page. Under these circumstances, it seems an SRG 2199 may also be required.
I hope a more knowledgeable fixed-wing examiner may be able to confirm or rubbish the above.
Assuming that there is no impediment to the examiner signing the applicant's revalidation page, there is no fee due to the CAA as no licencing action is being carried out by the Authority.