A browser-based billing app is easy to start with — until the connection drops on a busy evening and the queue at the counter starts growing.
What “works offline” should mean
Plenty of software says it works offline and means it shows you old data. For a shop, offline means:
- You can sign in. Not “your session survived” — a fresh start of the day, with no connection.
- You can issue a bill, with a real invoice number.
- Stock and customer balances update as you bill.
- Everything catches up on its own when the connection returns, without you re-entering anything.
The hard part: invoice numbers
GST requires invoice numbers to be consecutive and unique within a financial year for each registration. Offline, that is harder than it sounds. If two devices both bill from one series while disconnected, they can both issue “INV-1043” — and one of those invoices has to be cancelled and reissued.
There are two honest ways to solve it:
- One device owns the series. Only it issues numbers, so there is nothing to collide with.
- Each device has its own series (for example
INV-on the counter andINVW-in the browser), each consecutive on its own.
Software that “merges numbers later” is quietly breaking the rule.
What still needs internet
Some things genuinely do: sending a bill by email or WhatsApp, two-factor codes sent by message, and backing your data up. A good app tells you plainly when an action needs a connection, keeps what you typed, and lets everything else carry on.
In Billyng
The desktop app keeps your shop on your own computer. Sign-in, billing, stock and the khata all work with no connection. Each invoice takes the next number in that desktop’s series; the browser bills on its own series, so the two never collide. When you’re back online, your work backs up on its own. See it on our home page.