Invoices is where you decide how your GST documents are numbered and when an order gets its invoice, and the GST rate charged on delivery and fees. Mercayo issues the documents itself: a GST tax invoice for each order that charged GST, a bill of supply on the composition scheme, and a credit note when an issued invoice's order is cancelled or comes back undelivered. You only choose the prefixes and the moment. Open it from Settings › Invoices. Anyone who can see settings can open it; changing it needs the right to change settings, which the store's owner and admins have.
This page explains what Mercayo does. It is general guidance, not tax advice: ask your CA about numbering and GST on delivery for your business.
What You See
The title reads Invoices, with "Your invoice and credit note numbers, when invoices are made, and GST on delivery." There are two rows, Invoice Numbers and GST on Delivery, and one save bar (DISCARD, SAVE) for the page.
Invoice Numbers
"How your GST documents are numbered and when."
| Setting | What It Does | Default |
|---|---|---|
| Issue the GST Invoice | Confirm: when the order is confirmed. Fulfil: when it is shipped. An order shipped without an invoice always gets one then. | Confirm |
| Invoice Number Prefix | Up to 6 letters, digits, "-" or "/". Numbers read prefix, financial year, number: INV/2627/00001. | INV/ |
| Credit Note Number Prefix | Up to 6 letters, digits, "-" or "/", different from the invoice prefix. For example CN/2627/00001. | CN/ |
| Bill of Supply Number Prefix | Used instead of the invoice prefix while the store is on the composition scheme. Up to 6 letters, digits, "-" or "/". | BOS/ |
| Terms on Invoices | Printed at the foot of every invoice and credit note issued from now on (for example how to ask for a return). An issued document keeps the words it was issued with. | Empty |
| Print the Signature Picture | Prints your signature picture above "Authorised signatory" on documents issued from now on. | On |
| Invoice Look | Classic: black on white, Accent: titles and lines in your store's colour or Compact: smaller type, more lines on a page. | Classic |
| Logo on Invoices | Shows your logo at the top of invoices and credit notes (a PNG or JPEG logo). | On |
Under the card, Signature Picture: "A PNG or JPEG of your signature or stamp, printed above Authorised Signatory on documents issued from now on." VIEW SAMPLE INVOICE opens "a sample drawn with your look, terms and signature as they are now. Save your changes first." All your issued invoices and credit notes, and the GSTR-1 export, are in Orders › Invoices: see Invoices and the GSTR-1 Export.
When the Invoice Is Issued
- With Confirm, a cash on delivery order gets its invoice as soon as it is placed, and an order paid online when its payment is captured (for part payment on COD, when the part paid online arrives).
- With Fulfil, the invoice is issued when the order is shipped.
- Either way, an order that is shipped without an invoice gets one at that moment.
- An order that is still waiting for payment, or was cancelled, gets no invoice.
How Numbers Are Made
- A number is your prefix, the financial year, a "/" and a running number of at least five digits:
INV/2627/00001is the first invoice of the financial year 2026-27. - The financial year runs from 1 April to 31 March, by India's clock. On 1 April each series starts again at 00001.
- Each series runs on its own: invoices, bills of supply and credit notes each have their own numbers.
- Numbers are consecutive with no gaps and no repeats: two orders confirmed at the same moment wait for each other, and an order that fails gives its number back.
- A prefix is saved in capital letters and must start with a letter or digit. Without a trailing "/", the year follows straight on: the prefix
KOSHAgivesKOSHA2627/00001. - Changing the prefix during the year keeps the year's counter running:
INV/2627/00041, thenSHOP/2627/00042. The year stays one series. - A number is at most 16 characters. If yours would be longer, Mercayo drops the padding zeros first, then the "/", then the end of the prefix; it never stops invoicing.
GST on Delivery
"The GST rate charged on delivery."
| Setting | What It Does | Default |
|---|---|---|
| GST on Delivery and Fees | The GST rate charged on delivery and the COD fee, whatever the goods in the bag. 18% unless your accountant says otherwise. Between 0% and 40%. | 18% |
The same rate applies to gift wrap and to the COD charge of part payment. It is charged only when your store charges GST (regular registration in Taxes); like the goods, it is split into CGST and SGST within your state, or IGST to another state. If your prices include GST, the delivery price and fees you set already include it; if GST is added on top of your prices, it is added to them too. On the invoice, delivery and fees are printed under the HSN code of the bag's main item.
Which Document an Order Gets
| Your Registration (Taxes) | What the Order Charged | Document |
|---|---|---|
| Regular GST | GST | Tax invoice, with your invoice prefix |
| Composition scheme | No GST | Bill of supply, with your bill of supply prefix |
| Not registered | No GST | None (the order page and emails are the shopper's receipt) |
| Regular GST, registered after the order was placed | No GST | None |
When an order with an issued invoice or bill of supply is cancelled, or its parcel returns undelivered, Mercayo issues a credit note at once, numbered with your credit note prefix. Refunds and returns can credit chosen items.
How to Change Your Invoice Numbering
- Open Settings › Invoices.
- In Invoice Numbers, type your Invoice Number Prefix (for example
KJ/for a jewellery brand called Kanak Jewels), and a different Credit Note Number Prefix (for exampleKJCN/). - Choose Issue the GST Invoice: Confirm or Fulfil.
- Press SAVE. The next document uses the new prefix; numbers already issued stay as they are.
A prefix with a character other than letters, digits, "-" or "/", or longer than 6, is refused with "a document number prefix is 1 to 6 letters, digits, "-" or "/", starting with a letter or digit".
What Shoppers See
The shopper can download their GST invoice (or bill of supply) as a PDF from their order page once it is issued, and a credit note when their order is cancelled or returned. A business that added its GSTIN at checkout gets an invoice in its own name. The delivery and fee lines show their GST at your GST on Delivery and Fees rate.
Mercayo Controls
Every setting here can be set or limited by Mercayo for your store; a locked one shows Locked and "Set by Mercayo for your store." A prefix set by Mercayo is cleaned the same way as yours before it is used.
Good to Know
- An issued document never changes: it keeps everything it prints (your details, the buyer, the place of supply, items, charges, taxes and how it was paid), even if you later change products, prices or your store details. A mistake is corrected with a credit note.
- An invoice never blocks a sale. If issuing fails, the order goes on, the failure is written in the order's history, the number is not used, and staff can issue the invoice later from the order page.
- Changing Issue the GST Invoice affects orders from then on.
- Invoices and the GST export are covered in GST Invoices and Credit Notes.
- Changes here are recorded in the Activity Log.
Questions
Confirm or Fulfil: which should I choose?
With Confirm (the default), every confirmed order has its invoice straight away, which shoppers and businesses often want with their order. With Fulfil, invoices are made only for orders that leave your shop, so cancelled-before-shipping orders never need a credit note. Ask your CA which suits your filing.
Can I start my numbers from a number other than 1?
No. Each series starts at 00001 in each financial year and runs without gaps.
Why did my numbers start again at 00001?
A new financial year began on 1 April. The year in the number changes too, for example from 2627 to 2728.
Why is no invoice made for my orders?
Your store is not registered for regular GST (or the composition scheme) in Taxes, or the orders charged no GST. With Fulfil chosen, invoices also wait until the order ships.
Should GST on delivery be 18%?
18% is Mercayo's default. Some sellers charge delivery at the rate of the goods; set the rate your accountant advises.