Just check that your local Post Office does them. Sometimes you need to go to a big one in town. It will tell you on the Post Office site online what services they offer
I always hire a car when I visit my family. Last time we were stopped and asked for my International Driving Permit. The Police officer laughed when I showed it as they were hoping to be able to fine me lol. I would always advise to have it. Only about £7 from Post Office.