The prices of Royal Mail postage stamps will rise on 1 January 2021.

• A first-class stamp for a standard letter will rise from 76p to 85p
• A second-class stamp for a standard letter will rise from 65p to 66p
• A first-class stamp for a large letter will rise £1.15 to £1.29
• A second-class stamp for a large letter will rise from 88p to 96p

See here for full details: https://www.royalmail.com/prices2021