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Account form and transaction sub form work fine updating when not in a tab control when placing in tab control i get an error not finding account form. I want the account form to re-query to update balance when transaction form amount is changed

When you put a form on a tab control, it becomes a "subform control" on that tab, and that requires a change in your form references.

This is how a subform is usually referenced, before you put your form on a tab control:

     Forms!MyMainForm!MySubform

But after you put "MyMainForm" on a tab control, you need to reference the subform with this:

     Forms!FormWithTabs!SubformControlOnTab.Form!MySubform

This is one reason why Richard and many Access users aren't big fans of tab controls.  They change your form references completely and require complete code rewrites in a case like this.

If you want your form to work with or without tab control, you need to write some tricky VBA.

I solved this this problem by having an unbound control on form lined up under tab control looks same.  Then used a case statement in VBA for tab control page, then had forms load into unbound control based on the page index.  Other benefit speed, you don't have to have all the pages load at one time.  Working great.

Is the Tab Control not on Evil Access Stuff?

You can mimic tabs using Vehicle Maintenance or ABCD