The ANO says :
For revalidation of single-pilot single-engine piston aeroplane (land) class ratings and/or touring motor glider class ratings the applicant shall on single engine piston aeroplanes (land) and/or touring motor gliderssatisfy the requirements specified in paragraph 1.245(c)(1) of JAR–FCL1.
which says:
Revalidation by Test within 3 months
or
by Experience in the 12 months preceeding expiry.
The ANO then contradicts itself by saying:
Single-pilot single-engine class ratings
(i) Validity
"Single-pilot single-engine class ratings are valid for two years from the date of issue, or the date of expiry if revalidated within the period of three months preceding the date of expiry."
Three months should have read 12 months! It has been confused with the Renewal requirements. The error has been known about since it was published 5 years ago.