TNT Post has provided staff with a WAP-enabled mobile phone carbon calculator to allow them to measure their carbon emissions and offset these if they wish as part of its bid to become the lowest carbon emission mailing company.

The device will question employees about their lifestyle, such as how much driving they do, and will give them tips on how to reduce their carbon footprint and offset it through the Woodland Trust's tree planting programme.

Staff who wish to offset their carbon emissions can make tax-fee donations to the Woodland Trust through their mobile phone bill or through PayPal.

The product can be used any time and anywhere given that a significant number of TNT Post employees are not office based with computer access. TNT Post also plans to launch the carbon calculator to its customers later in the year.

Simon Dolph, head of corporate social responsibility at TNT Post, said: "Employees' personal carbon footprints double TNT Post's carbon emissions and we want to help our employees take environmental responsibility outside of work. If we can reduce employee carbon emissions by just 2%, the impact on the environment would be very real."