I replaced the rear pads on mine at 54,000 miles because the right side was wearing faster than the other, which I thought was a sticking caliper. They've been wearing evenly since then. As it was still under warranty I bought Hyundai pads. A lot more expensive but very good quality. I replaced the discs at 72,000 miles.
When you buy pads make sure they have the pip on the back to engage with the slot in the piston. When I went to GSF, none of the pads they had listed for my car were correct, and we opened up packs of Bendix, Brembo, and Drivetec to check. I ended up buying Pagid, which were correct and had the added bonus of being supplied with new shim plates as well. I still have those, as I decided later to buy the Hyundai ones.
If your MoT is coming up soon, I'd change the pads afterwards. If you change them now it might take some to bed in properly and attain maximum efficiency. I think minimum pad thickness for MoT fail is 1.5mm.