I don't follow the value of 1483. But if you only want one record per Zip code, then just include only one zip code in the table and make that the primary key.So fo 1483 there would be two combinations in the zip code table. Then the Dlookup of greater than one would kick in. Is that the easiest?
I would follow plog's instructions...but just for the record, the control source would be the table you're adding records to, not the Zip code table.Start a new blank form, not based on any table.
Add a text input on it to enter a zip code. <<---Doesn't this need a control source? Which I believe should be the actual ZipCode field in table zips?
Add 3 text inputs for City/County/State. These will not have any control source.