The new 2021 Collectors’ Coins – Decimal Issues of the UK (AKA Check Your Change) is now available to purchase. It can be found in the usual places, e.g. on Amazon:
Or from the publisher (signed copies also available):
The Check Your Change admin is Mr C H Perkins, publisher of numismatic publications in printed and eBook format. Author of "Collectors' Coins - Decimal Issues of the UK" and other books on British coins and related subjects.