Free POS System for Small Business – Google Apps Script

A full point of sale and inventory system running on Google Sheets, built for a wood trading business but structured to suit any stock-and-billing operation — grocery, hardware, garments, building materials. Login, role-based access, OTP password reset, A4 and thermal receipts and a complete inventory dashboard, with no server, no database and no monthly fee.

What it does

At the counter you pick a customer (or create one inline without leaving the sale), search items, and watch available stock count down as you add them. Take the full amount, a part payment, a custom figure or nothing at all, record the method — cash, bank, cheque or mobile wallet — and complete the sale. The receipt prints to A4 or a thermal roll, or saves as an image to send over WhatsApp. Anything unpaid lands in the customer's ledger, surfaces on the dashboard as an overdue reminder, and clears through the Receive Payment screen.

Highlights

• Duplicate Sale — repeat a regular customer's usual order in one click instead of rebuilding it
• Bulk CSV import with a downloadable template that skips rows already in the system
• Customer and supplier ledgers, with separate payment lists for each side
• Reports for profit and loss, sales summary, stock aging, customer analysis and shipments
• Four roles — admin, manager, cashier, warehouse staff — documented in an About App permission table
• Settings for app name, phone, address, currency symbol and the calculation formula used for stock
• SWR caching: sections open instantly from local cache and refresh silently in the background

Built with Claude Code

The first draft of both files was generated with a single Claude Code prompt in VS Code, then pasted into Apps Script and deployed. The video walks the entire path — installing the extension, running the prompt, deploying the web app, and running the demo-data function that builds every sheet and fills it with sample records so the system is usable immediately.

Who it is for

Timber and building-material traders, and any small retail or wholesale business that sells from stock, extends credit to regular customers and needs the ledger to stay straight.