Hell there, markbrunsell.

At this time, the option to customize and move the Mailing Address box of your check transactions is unavailable.

You'll want to visit our QuickBooks Online Blog regularly. From there, you'll be updated with the new features and enhancements that our developers are currently working on.

Please know that you can always visit our Help Articles page for QuickBooks Online in case you need some tips and related articles for your future reference.

If there's anything else that I can help you with, please let me know. I'll be always around to help.