Quote, Invoice & Inventory CRM – Google Sheets Apps Script

The three systems a small trading business actually needs, on one set of data: the customers, the paperwork that goes to them, and the stock that leaves when they buy. Quote, convert, invoice, deduct — without anything being typed twice.

Quote to invoice in one step

Quotations are generated and exported as PDF. When one is accepted it converts into an invoice rather than being re-entered, which removes both the work and the transcription error that comes with it. Invoices export as PDF too, ready to send.

Stock that follows the sales

Inventory is tracked alongside, so the items on an invoice come off the stock count. Quoting does not touch it — only a real sale does. That keeps the stock figure meaningful instead of drifting away from reality every time a quote is issued.

The customer side

Customer records tie the quotes, invoices and history together, so opening a customer shows the relationship rather than a name and a phone number. The dashboard runs real-time analytics over the whole thing — what has been quoted, what has converted, what has sold.

Access and storage

Authentication with role-based access decides who can issue documents and who can only look. Google Sheets holds everything, so the data is exportable and readable outside the app, and there is no hosting or database to pay for.