Asda and Zara
Matalan are really big fit, you've probably gone for the most roomy 3-4 clothes on the market there typically😅. I agree with the above, but also Nutmeg within morissons are small fit, I have to get 4-5 for my boy in there in tops, bottoms we can still get away with the 3-4, but he's on the big side x
H&M do 2-4 which is smaller
Supermarkets, & Primark = small Next & Matalan = big I also buy from the girls section for my boy comes up smaller
M&S x
Primark & Poundland.