Hi all
I have a retail business and sell a few lines on Amazon. One product I sell there is a keyring with a well known phrase on it, which has been in common use on keyrings, clothing and other novelties.

I've been contacted by a person who purports to own the UK brand name - his brand name is the same as the phrase on this keyring.

Assuming he is the real brand owner, can I legitimately sell an item with that phrase on it, as long as I make clear it is not produced by his brand? The product I have sold for about 10 years, though only a year or so on Amazon and he asserts he owned the brand since 2018. Surely you can't assert ownership of a brand and use that to shut down sales of things that were freely available prior to him registering the brand.

Hope someone can help!