What Is Face Value Good For?

From--http://www.mint.ca/store/mint/custo....U4oHAhbP9Zs

Can I redeem a collector coin at a bank or use it as currency to purchase goods or services?
All coins manufactured by the Mint are legal tender. However, unlike Canadian circulation coins, collector coins are non-circulating legal tender (NCLT). As such, these coins are not intended for daily commercial transactions and accepting them as payment or for redemption is at the discretion of businesses and financial institutions.

The Mint has a process in place to reimburse financial institutions the face value of redeemed NCLT coins, once they have accepted them from a customer and returned them to the Mint. In the event a bank branch is unaware of this procedure, customers are advised to contact the Mint with the coordinates of the bank branch, which will take steps to inform the branch of the redemption process.

As collector coins can only be redeemed at face value by businesses and financial institutions willing to accept them, it is recommended that individuals wishing to sell a collector coin first consult with a coin dealer, who is more likely to offer a price above face value.

There's a tonne of info on this already - here's one link:

https://goccf.com/t/123278

Bottom line is non-circulating legal tender (what these "coins" are) is not the same as legal tender. They can't just be spent.

If its a UK issue, take it to the post office or the bank of England. Both will accept coins at face value.

Though the coin is Canadian, and this topic has been discussed ad nauseum in the Canadian forums, I believe the OP is asking about the liquidity of non-circulation legal tender coins in other countries.