What do I do if my iPhone says the maximum number of free accounts have been activated on this iphone

I am trying to set up a new iCloud account on my phone, so that I do not continue to get my husbands iMessages. I set up a new apple id and could use it for iTunes, but when I try to use it for my iCloud, it gives me a message that states, "Cannot sign in The maximum number of free accounts have been activated on this iPhone"