I am a 74 year old Pensioner selling my stamp collection which I have been collecting for over 60 years. I have many, many thousands of QV stamps.
However, eBay messaged me last November and required me (no demanded) to upgrade to a business seller because of my volume of sales over the past 11 years. Also I had bought some stamps at auction, some to keep the rest that I don't want I list on eBay. Most of the time I barely break even.
No problem I thought so I upgraded to a business seller, don't mind paying the listing fee (36p per item) or the FVF. Those are the rules, also as many have said if you buy to resell you are a business seller.
I had a very interesting and informative conversation with a very helpful young lady from HMRC and to cut a long story short she said that I had to register for tax even though I was border line. So I registered.
I do not want to break the law or the rules. Being open and honest is the best policy, you can't go wrong.
Hope this helps