It is popular belief that door numbers are illegal, or they must be crossed out.
In fact, not having numbers or not crossing out numbers is nothing to do with law. Nowhere in C&U does it mention numbers.
All this crap about crossing out your numbers is from the MSA blue book. When you are not competing you should cross them out to avoid any confusion with competitors.
Legally you can have any damn number you want on your doors. It is advisable though to inform your insurance company, just in case.