What Rule 46 requires on a GST invoice, and the missing fields that get input tax credit claims rejected at filing time.
· GST · 6 min read · Updated
Why You Need a Proper GST Invoice Format
Under GST rules, every registered business must issue invoices in the prescribed format. Using the right format ensures compliance and avoids penalties.
The format matters for three reasons. It is what makes the invoice a valid tax document, so it is the document your customer relies on to claim input tax credit. It is what your accountant reconciles against when filing. And it is what stops a missing field from turning into a rejected credit claim six months later.
What to Include in Your GST Invoice
- Supplier name, address, and GSTIN
- Invoice number (sequential)
- Date of issue
- Recipient details
- HSN/SAC code
- Description of goods/services
- Quantity and unit
- Taxable value
- Tax rate and amount (CGST/SGST/IGST)
- Total amount
- Place of supply
- Signature
The HSN or SAC code on line 5 is the one most often left blank. For goods it is the four-digit HSN code, and for services the six-digit SAC code. If you are not sure which applies, the HSN and SAC code finder lists both with their rates.
Spreadsheet mistakes that cause a rejected ITC
Most rejected credit claims are not tax errors. They are formatting errors — a field stored in a way that loses its value. These are the five that come up repeatedly, and each one is a problem with how the spreadsheet holds the data rather than with the GST itself.
Keep the taxable value in its own column, separate from the line total. GST is a percentage of the taxable value, not of the gross figure, so a spreadsheet that only stores the total forces someone to back-calculate and get it wrong.
Keep the tax rate as a number (18) rather than a label ("18% GST"), otherwise the tax column cannot use it in a formula.
Give CGST and SGST separate columns, plus a third for IGST. An intra-state invoice needs the first two split evenly; an inter-state invoice puts the whole amount in IGST. One combined "tax" column cannot represent both.
Keep the HSN or SAC code as text, so a leading zero survives. Excel silently converts 0487 to 487 if the cell is treated as a number, and a mangled HSN code is a rejected invoice.
And keep the amount in words visible as plain text below the total, not buried in a formula. No calculation needs it, but buyers and auditors read it.
Why a template and a generated invoice are not the same thing
A blank template is a blank sheet with headings and a formula someone has to wire up. It is useful once, then it becomes a liability, because every invoice after that depends on the person remembering to drag the formula across three columns.
A generated invoice is already correct. The tax split is decided by the place of supply, the HSN code is on each line, and the amount in words already matches the total.
The practical test: if you are correcting last quarter's spreadsheet by hand every month, the format is the problem, not the software.
Getting it right from the start
If the mistakes above are the reason you are reading this, the faster fix is to stop hand-building the document. Create the invoice as normal in the free invoice generator and every Rule 46 field is placed by default — supplier and recipient GSTIN, place of supply, the HSN code on each line, the taxable value kept separate from the tax, and the amount in words. The tax split is decided by the place of supply rather than typed by hand.
It still exports as a real .xlsx file, so your accountant receives a spreadsheet they can pivot rather than retyping. If the specific thing you need to fix is the layout itself, the GST invoice template in Excel carries these fields with the columns already laid out and the tax formulas wired. For a quotation rather than a tax invoice, the quotation generator uses the same layout and converts to an invoice when the customer accepts.
Benefits of Getting the Format Right
- Fewer rejected input tax credit claims at filing time
- Invoices that reconcile against your GSTR-1 without rework
- A record your accountant can work from directly
- No dependency on one person remembering the layout
- Free to create, no signup required
Frequently Asked Questions
Is a spreadsheet invoice valid for GST? The format is correct, and it carries the mandatory fields. But an Excel file is a working record, not a registered e-invoice. If your aggregate turnover is at or above the e-invoicing threshold, the invoice still has to be registered on the IRP and carry an IRN and signed QR code, or your customer can have their input tax credit denied.
Can I edit the Excel file after downloading it? Yes, and that is usually the point of exporting one. Amounts are stored as real numbers, so a corrected rate or an added line re-totals rather than needing manual arithmetic.
Should the tax rate be 18% or 18 in my spreadsheet? Store the number 18. A label like "18% GST" is text and cannot be used in a formula.
What is the difference between HSN and SAC codes? HSN is for goods and SAC is for services. A goods invoice needs the HSN code, a service invoice needs the SAC code, and both belong on the line item.
Do I need the amount in words on a spreadsheet invoice? It is not needed for any calculation, but buyers and auditors read it, and it is one of the fields a tax invoice is expected to carry.
Create your first invoice at invoicemitra.in