I am about to get a 1 user / 3 PCs license. Does that mean only 1 NIS account?

I am about to get a 1 user /  3 PCs license key.  Does that mean only 1 account?  We have 2 NIS accounts in order to have separate Identify Safe vaults (with different, personal passwords).  Do I need to log out of one of them and have all 3 of our systems using the same NIS account when I apply the new product key?  Right now, only the initial NIS account reflects any subscriptions, if I go to the 'Account' link.