If you are using taking letters and parcels to the Post Office (or have a collection) you can print out a report that can be signed by a Royal Mail member of staff to confirm that the items have been posted. To do this following the following procedure:
Using One Stop Order Processing
You can get more information on One Stop Order Processing MC from the following link:
1 Select the PO Proof of Posting View.
2 Select the orders that are being posted.
3 Select the Print->Print Order View menu option.
4 When printing you may have to select A4 Landscape to fit the details onto a single sheet. You can also adjust the column widths on the screen before printing.