There isn't , you can have how much you want but you shouldn't spam otherwise you will end up getting banned .(Even if you get banned in one account you are not allowed to use the other ones as-well) .
Thanks for your reply, I was honestly curious because I saw people selling ten or more accounts at the same time.
I wont even bother with it myself, I like having only one account. Bet it is a big hassle to juggle multiple accounts.
No, you're allowed to have as many accounts as you want. But don't come crying when one of the accounts you sell gets in hand of a sig spammer and as a result you and all of your other alts get banned.
"Dont come crying" I was just asking a question on why or how this works. Never said that I would do it myself. Less judgement sil vous plait. But thanks for the information.