01 What a series is
GST needs one consecutive series per financial year. Octyn keeps one for each outlet, and separate ones for tax invoices and credit notes.
- Go to Station setup → Invoice numbers and pick the outlet.
- Choose This year or Next year at the top right.You can set up the current financial year and the next one.
- Read the two cards — Tax invoices and Credit notes.Each shows the last number issued and the next one. With nothing set, the first sale starts Octyn's format at 1, for example KHD/2627/1.
02 Joined in the middle of the year? Continue your numbering
If you issued invoices before Octyn, carry on from your last one so the year stays one series.
- On the Tax invoices card, choose Continue my numbering.
- Type the last invoice number you issued, exactly as printed — for example DI/SL/26-27/53.The card shows the next number as you type: DI/SL/26-27/54.
- Zero-padded numbers stay padded: CN/26-27/0099 continues as CN/26-27/0100.
- Choose Save series. Do the same on the Credit notes card if you issued credit notes.
03 A new financial year? Start a new series
Set up next year's series before 1 April, so the first sale of the year gets the right number.
- Choose Next year, then Start a new series on the card.
- Under Format, keep Octyn format or choose My own format.If you used your own format this year, Octyn suggests it with the year moved on — DI/SL/26-27/ becomes DI/SL/27-28/.
- Enter the First number — 1, or 0001 if your numbers are zero-padded — check the preview, and choose Save series.
04 The rules that keep it lawful
Octyn refuses a series that would break GST's consecutive-numbering rule.
- Once Octyn issues a number from a series, the card shows In use and the series can no longer be changed.
- A number can be at most 16 characters, using letters, digits, / and -, and needs a prefix before the running number.
- Each outlet and document type needs its own prefix, and a series cannot restart below a number already on a sale.
Done. Every counter invoice and credit note now carries the right number — on the receipt, the sales list and in GSTR-1's Documents issued. Open it in Octyn.