Numbering and terms
You set your numbering once, in the Set up numbering dialog that appears the first time you create an invoice. Afterwards, Payments → Settings → General shows Invoice prefix, Next invoice number, Payment prefix and Next payment number, which you can see but not change, under your default payment terms.
Numbering is a one-time setup
Read this before you create your first invoice.
Your numbering locks the moment you save it, and it locks automatically once your first invoice exists even if you never opened the dialog.
Once locked you cannot change:
- the invoice prefix
- the payment prefix
- the invoice starting number and payment starting number
- the number format
None of it can be changed from the app afterwards.
This is how invoice numbering has to work. Tax authorities in most countries require a sequence that can't be rewritten. Software that let you renumber issued invoices would be worthless as a record.
So spend two minutes on it now rather than living with a decision you made in a hurry.
What to set
Invoice prefix. The letters at the front. Starts at INV. Uppercase letters only, 1 to 5 of them. Anything else is stripped as you type, so Inv2 becomes INV.
Payment prefix. The same, for payments. It starts at PMT. RCT is another common choice.
Keeping the two apart is what stops confusion when one invoice is settled by three payments: one invoice number, three payment numbers, no ambiguity.
Invoice starting number and Payment starting number. Where each sequence begins, anywhere from 1 to 999,999.
Set these if you're moving from other software and want to carry on rather than restarting at 1. Continuing your existing sequence keeps your records readable across the move.
Number format. How many digits the number pads to: 3, 4, 5 or 6. INV-00001 versus INV-001. Five digits is the starting point.
The dialog previews First invoice and First payment as you type, so you can see the result before committing. Continue to invoice saves it and takes you into the invoice.
Numbers are never reused
Each number is assigned when the invoice is created and never given to anything else.
That means a deleted draft leaves a permanent gap in the sequence. If you create three drafts and delete the second, you'll have 001 and 003 with nothing between them.
This is correct and expected. Gaps are fine. Repeated numbers would not be.
Default payment terms
On the same General tab, above the numbering: the terms applied to new invoices, which work out a due date for you rather than you setting one each time.
The choices are Due on receipt, Due in 15 days, Due in 30 days and Due in 60 days. Unlike numbering, this is an ordinary setting you can change whenever you like, and it only affects invoices created afterwards.
The due date matters more than it looks. It's what makes an invoice overdue, and it's what reminders are timed from. An invoice without one sits unpaid and unchased indefinitely.
Saving
The General tab shares one save bar with the rest of payment settings. It appears as Unsaved changes the moment something changes, with Save and Discard.