Ownership transfer

Only the seller can tell you why the tag won't transfer.  If the system is European in origin, having originated in a country where Dell is now prohibited by law from supporting a system (i.e., Russia, Belarus), that could be one reason.  So can a system of indeterminate (grey-market) origin.

If the seller can't tell you, return the system to them for a refund.

Laptop is from UK its still has label from UK company. I live in Poland.

I have previous owner data from seller but as i wrote in first post dell send me e-mail:

This service tag is not eligible for ownership transfer. Please contact Dell Customer Care for further assistance, but there is no instruction how to contact them and phone numer is not working...

What do you mean by (gray-market) orgin? You mean like insurance scam, taxes scam or ...?

You're asking in the wrong place -- contact your seller.  

Sorry. I don't understand your answer.

Why is it wrong place to ask?

I have e-mail from Dell telling me to contact Customer Care.

And you are telling me i shouldn't contact Customer Care?

They likely won't have any more information than what the message you've received says.  That is why you should contact the seller of the system -- if they cannot provide the information, return the system to them for a refund, or accept that you have no warranty or support on the system.

There are many reasons why a system might show up as ineligible for warranty transfer, but the ultimate arbiter of that is your seller.