I Built a Complete POS System for Mobile Phone Shops (WhatsApp + Repairs + Inventory)

A point of sale built specifically for mobile phone shops — because a phone shop is not a grocery. You sell handsets and accessories, you take devices in for repair, you buy used phones off customers, and you sell on instalments. This handles all four in one system on Google Sheets, with a permission matrix you edit without touching code.

IMEI lookup ties it together

Every handset that passes through the shop carries its IMEI — bought as used stock, brought in for repair, sold to a customer. Type an IMEI into the lookup and you get the full history of that device across your whole business in one screen. That is the difference between a generic POS and one built for this trade.

What it does

At the counter, search stock, pick a walk-in or saved customer, apply a discount, take payment and let it calculate the change — then print A4 or thermal, at 58mm or 80mm. Repairs are logged against a technician with the device IMEI, passcode, warranty days and the parts used, and those parts come straight out of inventory. Used-phone purchases record ID type, ID image, grade, battery health and screen and body condition, and print a purchase contract. Instalment plans track what is paid and what is due, with WhatsApp reminders.

Highlights

• Returns that restock automatically, per line, with a reason and refund method
• Cash drawer with opening float, expected, counted and the variance when you close the till
• Loyalty points with earn rate and redemption value you configure — spend a set amount, earn a point, redeem it as tender
• Supplier profiles showing exactly which products came from whom
• Customer profiles combining their sales, repairs and payments in one view
• Role and permission matrix — take edit rights off an employee and it applies immediately, no redeploy
• Reports for revenue, collected, profit and loss, top products and payment breakdown

Who it is for

Mobile phone retailers and repair shops, especially those who also buy used handsets or sell on instalments and currently track repairs in a notebook.