Sorry for the duplicates. And I apologize for useing my phone. I’ll post a full pic when I get to work tomorrow.

Hi Ryan, Below I'll link several videos related to importing from and exporting to Excel as well as linking an Excel workbook as a table and being able to edit/manage data that way. Following the techniques in these videos, you'd be able to create and manage both of your excel sheets. If you save the newly received/returned excel files from your customer to a designated folder, it is also possible to set up your database to just look in that folder for all new sheets in the folder and import the information with a click from Access.

Import Excel
Excel Import Cleanup
Excel Import Cleanup 2
Export to Excel
Edit Linked Excel Data
Link to Excel

Since you cannot control input on an excel spreadsheet I would consider creating an accdb file that is not split.  You can code it to them by using a simple text file in the folder with their customer number in the file.  They can then export and send you the information.

Alternatively take a look at a web forms solution that you can use to to import from.   You can export your menu there as well.  If you're using excel for anything other than a caluclator app you're using the wrong tool for the job