Is taking off the tags on mattress's illegal?

It's only illegal for a retailer to remove the tag, as the tag's purpose is to inform the consumer of the mattress's materials. Once you buy the mattress, you're free to rip it off.

If you remove the tag, the company will not honor the warranty. The code on the tag tells them where it was made, when it was made and then and only then can they honor the warranty. no tag, no warranty!!!