Srs, having never shipped anything beyond a letter to the UK: How much are we talking?

Depending on how many categories you have, it’ll only take 3-4 hours to set up something like this (I’m including buying the supplies, typing up the labels, printing the labels, then sticking the labels on or in your tabs.) I have to re-create about 80 files in one batch each year—I agree that it’s a pain, but easy to get through if you have music or a good podcast or audiobook.

White file folders on Amazon (may or may not have shipping to the UK):

https://www.amazon.com/ADVANTUS-CORPORATION-Cropper-Hanging-Folders/dp/B00161OR9M

https://www.amazon.com/Russell-Hazel-Hanging-Folders-82372/dp/B00NVEF5G6

If you’re okay with gray, Amazon Basics has a decently-priced option:

https://www.amazon.com/Pendaflex-Recycled-Hanging-Folders-81604/dp/B0006HXD74

I suspect that you won’t find many plain white hanging file folder options because of the extra cost/effort to bleach paper pulp.