Examples? Screenshots?

Please be more specific. See Rule #2.

PricingT1 is the table to update

The field [Cost] is in both tables. You have to include the Table Name so Access knows what field you are referring to. Basically, is the field in Table One or Table Two?

Out of curiosity, is there a reason why you have 2 Tables with exactly the same structure?

You have to specify the table because there are two "Cost" fields. It doesn't know to use PricingT1.Cost or PricingT2.Cost if you could just put "Cost"

Kevin, Those are copies of the actual table that I use in the DB so I don't mess up the good table. It's easier to copy and try than recreate. They will be deleted once I get the update query right. Thanks for the help I understand it now