How do I make a cashier program for my shop?

Yes. Any Windows program can print through the printers set up in the system: a thermal receipt printer, an ordinary office printer or a label printer. The condition is that the printer's driver is installed and a test page prints from Windows itself. What remains is setting the paper size and receipt layout inside the program, and testing on your own device before you rely on it.

An invoice program needs your business details and tax number, a list of customers and items, and a VAT rate applied to each line: 15% in Saudi Arabia and 5% in the UAE, in general terms. It works out the amount before tax, the tax and the total, gives every invoice a sequential number and prints it. Official e-invoicing requirements should be checked with the official source or your accountant.

An inventory program rests on three things: a product list where each item has a code, a quantity and a minimum level; stock movements in and out recorded as they happen; and an alert when an item runs low. Start with a physical count for opening balances, then record every movement. Build it in a spreadsheet, buy a package, or describe it to an AI builder.

A program works offline when two things are true: it is installed on the computer itself rather than opened in a browser, and its data is stored in a local database on that machine. Then it opens, sells and prints even if the connection is down for days. The trade-off is that the data stays on that one computer, and backing it up is your own responsibility.