Opening a new checking account and moving all of you existing financial relationships can be a problem. It takes a lot of time and you're sure to miss something meaning late payments and credit report issues. There are some basic steps you can take when changing to a new checking account to minimize the hassle.
The first step is the most obvious one. Open the account and get the information you need: account number and routing number. Order personalized checks if you need them. In other words, be prepared.
Make a detailed list of all automated withdrawals and deposits from your current primary checking account. The best way to do this is to simply watch the account for a period of two to three months so that you pick up as many of these as possible.
Make sure you've accounted for everything outstanding so there are no nasty surprises during the transition. Figure out what you have in the old account down to the cent so that you can avoid overdraft dangers.
I find this is easiest to do by switching over the deposits a bit earlier than the withdrawals, so that there is money already in the new account when deposits begin to be set up. I'm also incredibly careful about such things.
By maintaining a balance you can catch any missing deposits or withdrawals that may come through. Even though it might feel like the balance in the old account is just sitting there wasting time, it's actually there to protect you against your own poor memory. Just be patient and give it several months; you might surprise yourself.
Be sure to leave a correct address behind. You might also want to end other services at that bank, such as a safety deposit box.