Can forms be migrated between accounts?

I have a conundrum: I've used my account to set up various webforms on clients' websites. Now, one particularly large client has, (all on its own) over time outgrown the free account level, and would like to transfer control of the account to them. 

I don't see a 'transfer form between accounts' function. Can I perhaps get some help transferring forms to a new account for my own use, so that I can cut my original one loose? I'd also like to take my username with me... since its sort of my trademark. 

Any way to gracefully split these, without hand-building all the forms, integrations, notifiers, etc, etc, etc, and then re-embedding the new code everywhere?