With a thickness of 3.15mm, the coin was designed to be easy to make out from other loose change, although this has not stopped it from being targeted by counterfeiters - and almost three in every 100 pound coins are thought to be duds.
Ways to spot a fake include looking at how even the lettering is, seeing if the milled edge of the coin is even and well-defined and examining the colour. Genuine £1 coins which have been in circulation for some time appear more shiny and golden.
More information about how to spot a fake £1 coin is on the Royal Mint's website here.
More top news
Friday morning's forecast for the west of the region
Friday morning's forecast for the east of the region
Surrey Heath MP Michael Gove has confirmed he will stand for leadership of the Conservative party - taking on Maidenhead MP Theresa May