Wholesale carbon values for 2023/24

We are pleased to provide our Wholesale Letters Business Unit carbon values for the period 1 April 2023 to 31 March 2024.

Carbon Unit Values for Wholesale Letters Business Unit


gCO2e 2022/23 per unit

gCO2e 2023/24 per unit

Total Wholesale






Large Letter






Our carbon unit values for Royal Mail Wholesale have increased slightly compared to last year. This is down to the decline in total Letter and Large Letter volumes of circa 9%, whilst emissions in the same period fell around 2%. As the ‘per item’ emissions are an intensity metric it means that if Letter and Large Letter volumes fall faster than the decarbonisation, the per item number goes up. This is not reflective of our encouraging performance on emissions reduction of 2% since last year and 8% since our base year of 2020/21.

Our ESG Report for 2023/4 was published today and will be accompanied by an external assurance statement.


Royal Mail Calculation Method

Carbon per Letter and Large Letter for Wholesale within Royal Mail is calculated in four steps:

  1. Calculating domestic mail emissions: These include all Scope 1-2 emissions and Scope 3 Upstream transportation and distribution (domestic). This is for all Royal Mail activities and subsidiaries including head offices.
  2. Split emissions for parcels and letters: The greater majority of our network is blended and emissions are split on % revenue of our letters business versus our parcels businesses.
  3. Divide letter emissions by letter volume: Total emissions attributed to letters are then divided by the reported letter volumes as stated in our annual report and account.
  4. Split emissions for Wholesale: Total Wholesale emissions are then separated and divided by the reported Wholesale volumes.

These figures remain fixed for each financial year and are updated upon release of our Annual Report and Accounts and ESG Report. We seek to continually improve our data reporting practices and we will re-state prior figures to ensure direct comparison where material method changes occur.