Is it double counting if my supplier's Scope 1 also appears in my Scope 3?
No. Scope 3 is built to overlap with other companies' Scope 1 and 2, and the GHG Protocol accepts that overlap between inventories. Double counting is a problem when you count the same emissions twice inside your own inventory, when two parties claim the same reduction or offset, or when company inventories are added together.
Why the overlap is intended
Each company reports the emissions it causes directly (Scope 1), through bought energy (Scope 2) and across its value chain (Scope 3). The same tonne from a supplier's furnace is that supplier's Scope 1 and its customer's Scope 3 Category 1. The overlap lets both act on it: the supplier by changing fuel, the customer by choosing suppliers and designs.
Double counting you must avoid
- Within your inventory: the same emissions in two scopes or categories, such as freight paid inside a goods invoice counted in Category 1 and again in Category 4.
- Within one category: one purchase counted twice, for example from the invoice and the delivery note, or from both spend and quantity.
- Claims: you and your supplier both selling or retiring credits for the same reduction, or both calling it your own offset.
- Aggregation: adding the inventories of a supplier and its customer to get a sector total. Use Scope 1 only for that.
How to keep your own inventory clean
- Give every purchase one home: one scope and one category.
- Split freight out of goods invoices when it is billed separately, and record it only once.
- Treat leased assets the same way every year, either in Scope 1 and 2 or in Category 8, not both.
- Remove duplicate documents before totalling.
Worked example: one supplier, two inventories
- Supplier's Scope 1 for the year: 1,000 t CO2e
- You buy 20% of the supplier's output
- Your Scope 3 Category 1 from this supplier: 1,000 x 0.20 = 200 t CO2e
- The supplier still reports all 1,000 t in its Scope 1, and both reports are correct
This uses a simple output share. In practice, allocate by the quantity of product you bought and the supplier's emissions per unit.
What Senseible does here
Senseible keeps Scope 3 lines in a separate supplier evidence trail from your Scope 1 and 2, and its SHA-256 fingerprint stops the same file being counted twice. It catches identical files only, so the same purchase on two different documents still needs your review.
Sources: GHG Protocol Corporate Value Chain (Scope 3) Standard (2011)
Last reviewed 2026-10-15.