Do trailers only used for storage need to be on O Licence?

Hi, thanks for the replies, I have decided to relocate the trailers back to their home sites and look at other storage options. I think it may be asking for trouble keeping them where they are. Although we have no intention to use them, it may be difficult to convince someone of this, both being perfectly useable. Another point to note is that we don’t actually have any tractor units at this site, units are based at another O Licence site with other trailers within the same company. I have a fleet of 7.5t’s and 17T’s, one broken trailer on our O Licence and 2x working trailers that we would have to get someone in to move for us. thanks for your help.