If you're on the curvy side of things (like I am myself) buying swimwear often means that online shops are the only way to go as retailers tend not to stock larger sizes on their rails in store.
I'm writing to warn you off buying from a particular online store (that may appear in your reels or feeds online based on the almighty 'algorithm').
That online store is this one:
https://www.curvyshe.co.uk/
This is not to be confused with a lingerie online shop with a very similar name.
If items don't fit and you want to return them (which as a consumer, is your right to do so) it's a nightmare.
I have no idea, nor do I want to at this point, where their primary office which I would expect the goods to be dispatched from and returned to. Apparently, the only place to return to is in the USA even though the site has a '.co.uk' qualifier on it.
I'm not sure how you would find out where a company operates out of and where their distribution centres and returns locations are but I would recommend that if you absolutely must buy your swimwear online, to stay well away from the above site/business when doing it.
Just a bit of a consumer advice.