I had never heard of this free, certified check that you can have your bank send for you!! Whaaaaaat?!?!?! I mail a check like an old lady in the 1940s. (Or, you know, up until the 2000s.)
And in terms of reimbursement, my boyfriend gets paid on the 5th and 20th of each month, so we’ve worked it out where he pays me half of next month’s rent from the 20th check, and the rest from the 5th check. So I’ve got half of his dollars in my account before I write the check, and should my landlord deposit the check before the 5th of the month (which has never ever ever ever happened), I just have to have enough in my account to cover that last 1/4 of the amount. And we use our bank’s app to transfer money back and forth to each other, so that part is easy and fast.
I’ve always been curious about that whole joint-bank-account-purely-for-bills thing, but I’m too lazy to convert us away from our system at this point.