I am currently working on a project, I have created an excel sheet that has multiple tabs with in it, all of which has different data entered into each of the fields in each tab.

This excel sheet gets sent out to clients and they fill out their information into it, and send it back to me.(this process is on-going, so they just use a copy of the original excel file I sent them)

When I receive the excel sheet, I then am importing it into Access, which will store all this information( this access database is storing all information, the excel files are just the temporary storage until imported to Access.

What my problem is that in my excel sheet, 2 of the tabs have to be linked with a unique auto number, but I cannot do that in the excel sheet since it will be used multiple times so the auto number would be the same every time, and the excel sheet it used by hundreds of different people with their individual information.

So for in my Access Database, I import the excel sheets individually for each tab, which goes into pre-existing tables in access.

So my question is, is there a way, in Access, to assign a unique number to 2 different excel imported tabs, without having any duplicate numbers? I've tried just to use a auto number field, but the 2 tables that are linked by the unique number tend to not always line up correctly.