Free POS with Salesperson Invoice Numbers – Google Sheets

A till with a product grid you tap, and one thing most POS builds on Sheets do not have: each salesperson gets their own invoice series.

Selling

Products show as a grid of images with prices. Tap one to put it on the bill, tap again to add another, or use the plus and minus controls to adjust. The total moves as you go. It is built for a touchscreen or a phone at a counter rather than for typing item codes.

Invoice numbers per salesperson

This is the part worth understanding. Each salesperson is set up with their own prefix — AD, AH, whatever you choose — and their invoices run on their own sequence: AD-001, AD-002, while another person is on AH-001. The next number is worked out in code by reading that person's last invoice and adding one, not by a spreadsheet formula, so it holds up when several people are selling at once. For a shop paying commission or a business with more than one counter, invoices that identify who raised them are the difference between reconciling sales and guessing at them.

The guardrail

Posting without choosing a salesperson is refused with a clear message. An unattributed sale is the one you cannot fix afterwards, so the system will not record one.

Setting it up

Items carry an ID, description, price and an image URL in the items sheet. The currency symbol is set in one place in the script — change PKR to USD or anything else and the whole app follows. Sales land in the sheet with the invoice number, salesperson, customer name, ID and contact, and each item with its quantity and price, ready to total however you like.