Yes, it's a counterstamp--a post mint event, not an error. There are a small number of collectors who like counterstamped coins and will pay a bit over face value for them--if they are attracted to particular examples.
Maybe someone just messing around - at my school we had a set of punches in the metal workshop with letters and numbers, and I'm sure a few of us punched random letters into the odd 1p or 2p coin!
Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Coin Community assumes no liability for errors. Copyright 2005 - 2026 Coin Community Family- all rights reserved worldwide. Use of any images or content on this website without prior written permission of Coin Community or the original lender is strictly prohibited. Contact Us | Advertise Here | Privacy Policy / Terms of Use