One of the rarest is the Kew’s Garden 50p, which was designed to mark the 250th anniversary of the gardens in 2009. Only 210,000 coins were ever minted with this design. The Kew Gardens 50p sells for ...

You can also take your currency to a local coin dealer who also specializes in rare bills. Or you can go to an online forum like r/Currency and ask about your bill there. You may need to take ...