Although this is a American website there are definitely some British people who read this. Most the stuff on this website is made for survival in the USA but survival in UK is much different for a variety of reasons, However, we do have our own advantages, strong castles to be protected behind, we are also surrounded by sea so wouldn't have the problem of say France's zombies coming to us etc.Some people might say our lack of guns is weakness, however it may also save many lifes e.g. bandits might not have them, unless they are rogue military or managed to steal them.
So anyone living in the UK is going to have to improvise. Most people are not going to stumble across a army base, weapons shop or pick up guns laying around. So each group would would have to rely mainly on melee weaponry. Our best weapons would probably be tools, we may also use bows.
Base defence would also be different due to lack of ranged weaponry, though we do make up for this by not needing them in some cases. 3 foot thick stone walls are going to be hard to get through even if there is a hundred zombies.
The best idea for Britons is to either go North into Scotland or you can choose to stay in well fortified castles, depending on where you are each choice has its benefits and advantages.
There is a chance that the infection might not get to Britain, as a sea-locked nation the borders might close and stop it getting in from other countries.