My supplier is a GST composition dealer and gives a bill of supply. Can I use it as carbon evidence?

Yes, if it shows what was supplied and how much. A bill of supply is a valid GST document from a composition dealer, but quantity is often missing from it. If it gives only an amount, get the delivery challan or weighbridge slip for the quantity, or use a spend-based estimate labelled as such.

Why your supplier issues a bill of supply

A registered supplier who pays tax under the composition scheme, or who supplies only exempt goods or services, issues a bill of supply instead of a tax invoice. A composition dealer cannot charge GST, so the bill shows no tax and you claim no input credit on it.

What the bill will and will not show

• Supplier name, address and GSTIN, a serial number and the date.
• Your details if you are registered, a description of the goods or service, the HSN or SAC code and the value.
• Quantity is not something to count on. Many bills print it; many give only a description and a rupee amount.
• For the full list of required contents, read Rule 49 of the CGST Rules on the CBIC website.

Turning it into activity data

1. Description and HSN tell you the material or fuel.
2. Quantity and unit, if printed, are your activity data. Multiply by a published factor.
3. If no quantity, match the bill to the delivery challan, weighbridge slip, gate entry or stock register for the same date.
4. If nothing gives a quantity, use the amount for a spend-based estimate and label it so.

How strong is it as evidence

A bill of supply comes from a registered supplier and carries their GSTIN, so it can be traced back to them. Do not rely on your GSTR-2B to confirm it, since that statement is built for input tax credit, which a bill of supply does not give. Keep the paper or PDF and the payment record together.

Worked example: coal from a composition dealer

• Bill of supply: coal, HSN 2701, ₹42,000, no quantity printed
• Weighbridge slip, same date and vehicle: 3,500 kg net
• Emissions: 3,500 x 2.42 kg CO2 per kg = 8,470 kg CO2, about 8.5 t, Scope 1 if burnt on site

The coal factor is the IPCC 2006 default used by Senseible. The quantity comes from the weighbridge slip, not the rupee amount.

What Senseible does here

Senseible reads a bill of supply like any other invoice. When a line prints a quantity it applies the published factor; when it does not, the line shows Needs Data until a delivery document gives the quantity, or Senseible provides a spend-based estimate labelled with wider uncertainty.

• GST e-invoice fields for carbon accounting
• Fuel invoice with amount only
• What Needs Data means
• Coal factor for India

Sources: GHG Protocol Corporate Standard, Chapter 7, Managing inventory quality, 2006 IPCC Guidelines, Volume 2 Energy (coal default)

Last reviewed 2026-10-18. CBIC and GSTN pages could not be read on 2026-10-18; bill of supply contents are described generally. Check CGST Rule 49 on cbic-gst.gov.in for the current list.