Okay, I may have to do some testing to make sure what I'm about to say actually works, but this is how I see it. Let's say you have a linked table called FinanceSystemCSV, which is linked to the Excel/CSV file. Let's also say it has 10 rows of customers in it. Now, you also have a Customers table with only the 10 Account Codes in it, matching the ones from the finance system, plus some fields you want to keep track, that are not included in the finance system. Okay, so if you export a new CSV file from the finance system, and it now has 11 customers listed, then your FinanceSystemCSV table should show all 11 customers. However, your Customers table will still only have the previous 10 customer. To get the new customer added to your local table, you will have to execute an APPEND query. Likewise, if the new CSV file has less customers, and you want to remove the extra one from your table, then you will have to execute a DELETE query. You can perform these actions automatically, using a macro or procedure, when your db opens up.