Is this allowed?

[TehForum]

My friend has got a vBulletin license, which he's not using and has offered to let me use it for free for a month or two, so I would like to install it onto my website, but hopefully in a month or two time I will have my own vBulletin license, so can I change the vBulletin license to my new one if I do purchase my own?

[Disasterpiece]

you could always redownload the install files, because your license id is embedded in the vb core files.

Maybe you can combine this procedure with an update

[BirdOPrey5]

Technically no, you may not "lend" or rent out a vBulletin license.

Your friend could make his own forum and appoint you as an administrator and let you do whatever you want- and later when you get your own VB license he can "sell" you the site for $1 or whatever, but technically he needs to own the site his license is being used on.

You should probably ask on the pre-sales section of vbulletin.com for license issues.