Parcelforce has calculated the cost of the average amount of carbon emitted per parcel as 10p for UK deliveries and 20p for international deliveries.
Customers booking online have the option to donate half that amount, with Parcelforce contibuting the other half. The money will be invested in a programme run by woodland protection charity The Woodland Trust.
Parcelforce is also working with a number of its account customers who want to achieve carbon-neutral status for their deliveries.
Vanessa Leeson, Parcelforce managing director, said the move is a first in the UK express parcels market, and part of a wider approach by the company to carbon management.
She said: "Our business uses renewable energy in our buildings, bio-diesel in our vehicle fleet and proactively seeks to increase energy efficiency where practical.
"While we'd never force carbon offset onto our customers, many of them are telling us that they will choose the commitment."
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