Non vat registered companies?

[helpimcrap]

Hi all,
Are there any issues I should be aware of if dealing with non vat registered people like plumbers or carpenters etc?

Someone is trying to get a bathroom fitted but they told them they weren't vat registered.

Would this affect warranty of the work etc? I'm being overcautious because it's a lot of money to lose potentially.

 

[helpimcrap]

Thank you. I told them to check with neighbours they know who have it done to check work etc.
I know about the £85k limit but I didn't want to advise for sure.