Old pound coins won't be accepted after Sunday 15th October 2017
As you are probably aware, the round £1 coin will no longer be legal tender after Sunday the 15th of October, as it is fully replaced by the 12-sided version.
Following the new 12-sided £1 coin’s introduction on 28 March 2017, we are approaching the end of a six month period when the older, round £1 coin and the new 12-sided £1 coin are in circulation at the same time. The older, round £1 coin will lose its legal tender status at midnight on 15 October 2017.
After the 15 October, the older, round £1 coin won't be widely accepted as a form of payment for goods and services, but can continue to be deposited into bank accounts at most High Street Banks in the UK.
For further information please see the official Royal Mint website: