Offline invoicing sounds like a niche requirement until you spend an afternoon in a plant room, or on a site with one bar of signal that belongs to somebody else’s network.
The work is finished, the customer is standing there, and the thing stopping you issuing a document is a login screen that will not load.
Why this site keeps working
Every generator here runs entirely in your browser. There is no account, no server call when you type, and nothing transmitted at any point. The page is HTML, CSS and a small amount of JavaScript, and once it has loaded it does not need the network again.
That has an ordinary consequence: open a page while you have signal, and it keeps working after you lose it.
What still works with no connection
Everything the sheet does:
- Typing, adding and removing lines.
- The arithmetic, including tax, discounts and the balance due.
- Currency selection and formatting.
- The QR code and barcode, which are generated on the page rather than fetched.
- Saving the sheet to a file.
- Loading a sheet you saved earlier.
- Printing, and saving as PDF.
What does not work is navigating to a page you have not already loaded, since that is a fresh request.
The practical routine
Before you leave, open the documents you expect to need and leave the tabs open. An invoice, a receipt and a job card covers most site work.
On site, fill in the sheet and save the file to the device. Print or export to PDF if the customer wants something immediately. Back at the office or in signal, send it.
Printing on site
If there is a printer, print. If there is not, use your browser’s print dialog and choose Save as PDF, which is entirely local.
On a phone the same dialog is behind the Share or Print action. Printable invoices covers the paper settings, and invoicing on your phone covers the mobile flow.
Getting a signature
Print two copies, sign both, leave one. That is still the fastest way to close a job on site, and it does not depend on anything working.
If you cannot print, a photograph of the signed screen is not a document. Fill in the job card, have the customer sign the printed copy later, and note on the sheet who approved what and when. How to write a job card covers the fields that matter for approval.
Keep the files, not the tab
The one real risk is closing the tab before saving. Nothing is stored for you, which is the point, so the saved file is the only copy.
Save early and save again after any substantial edit. Where to keep your invoice files covers a folder structure that survives a lost device.
Battery, not bandwidth
The constraint on a long day is usually power rather than signal. A sheet with fifty lines is still just a page, but a phone that has been navigating all afternoon is not.
Print or save as soon as the document is complete rather than at the end of the day.
What “nothing is transmitted” means in practice
It is worth being concrete, because the phrase is used loosely elsewhere.
The pages here are static files. When you type a customer name, no request is made. When the sheet calculates a total, no request is made. When it draws a QR code, no request is made. When you save, the file is written by your browser to your device.
There is no account to create, so there is nothing to log in to, and no session that can expire while you are underground. The privacy page says the same thing in fewer words.
Loading the pages you will need
The one requirement is that a page has been fetched at least once. Before heading somewhere without signal:
- Open each document you might need, in its own tab.
- Load your saved template into one of them, so the details are already in.
- Leave the tabs open. Do not refresh them on site.
A refresh is a fresh request, and a refresh with no signal is a blank page and a lost sheet.
Phones sleep, tabs get evicted
The realistic failure on a long day is not the network. It is a phone under memory pressure discarding a background tab, which comes back blank when you return to it.
The defence is the same as everywhere else: save the file after any substantial edit. A saved sheet reopens; a discarded tab does not.
Two copies on site
Where a signature matters, print two. One for the customer, one for you, both signed. Paper does not require power, signal or a working printer at the other end.
For trades this is the job card routine, and it closes the job while everybody is still standing there. Invoicing for tradespeople covers the rest of that pattern.
No connection is the default, not a fallback
This is worth saying plainly. The site does not have an offline mode, because it does not have an online mode. Nothing leaves the browser at any point, connected or not, which is what the privacy page says and what the code does.
Open the invoice maker once, and it works wherever the job is.