Handling last month rent, how to charge the difference?

[Linda Roberts]

My tenants have lived in the house for several years. During this time, the rent has increased by $650. How do you handle the difference between the original last month's rent and the current rent? Do you require tenants to add the difference to the last month's payment each year with a rent increase? Is this stated in the lease agreement?

[Bill B.]

Are you sure that checks still good? I’m not sure a check from “several years ago” is still good. 

I would bring it up now. Tell them because the check is old and the amounts don’t match you’d like to return that check to them when you receive a new check for the correct amount. 

Ps. If by “the check is still with me.” You meant you deposited it. (I don’t collect last month’s rent but if I did I would have noted in the lease I was going to deposit it.) Then yes. Simply state they owe current rent minus prepaid rent amount.