To delete a document

  1. Open the Purchases/Sales and select Documents list
  2. Select the document you want to delete and double click on it
  3. Click Menu (top right) -> Edit -> Lock old documents edit/delete capability
  4. To delete the document you see, tap the deletion button that appeared
Beware this process is not reversible.
This function is the same for all kinds of documents such as receipts, invoices, quotes, orders etc.