Hi JoeR 

This was taken from the .gov website on entry into South Korea 

Regular entry requirements

Visas

If you have a British Citizen passport you can enter South Korea as a tourist for up to 90 days without a visa. You must also have an onward or return ticket. It’s illegal to work on a tourist visa, whether as a teacher or in any other capacity.

As you are on the Sex offenders register your issue will be if the PPU issue a green notice via Interpol, this will then give the Korea Authorities the heads up that you have an issue and might turn you away.

This is the issue while on the SOR so some times is always best to go to these places once your off the SOR 

Because it is also important to remember that the UK does not give police national computer access to other countries.

Hey,
Was wondering if anyone on a SOR has been to South Korea and if so were you allowed in and did you face any issues. i cant find any information and my PPU has not been helpful. I'm weary as I know S. Korea post their SOR online for all to access to I'm hesistant. I would love to visit but having been previously refused entry to the Phillipines I would not like to repeat that.Would love to hear if anyone has had any luck.