This is the recently introduced 'jig-saw' twenty pence, issued in the second half of 2008, as part of a design change to all the British definitive (non-commemorative) circulation type coins. As you can see, the obverse is dated, and the reverse is not. 20p coins have hit the news big-time here in the UK, following a clever bit of PR by a coin marketing company, which has given them thousands of pounds worth of free advertising.