In order to massively correct our product availability (from excel, csv) there’s a “Stocktaking” document by default (export of goods).

We choose (upper right part) –> Edit –> Import document lines from file:

We select an excel, csv file from our computer (in case of csv, we change the separator accordingly, usually 😉 and we choose the fields that correspond with our column data (usually we only need Product ID and Quantity):

Then we select “Import” and when it asks for confirmation to “Enter in the quantity field the total availability of the item?”, we choose “Yes”.

The quantity in each product line will automatically be the difference between the current availability and the one we want to be in the end, so that after we save this document we have the desired result.