Wikipedia
Whistl
Whistl, formerly TNT Post UK, is a postal delivery company operating in the United Kingdom. The company primarily competes with UK Mail, UPS, Parcelforce, DHL, Hermes, Royal Mail and Yodel. It processes over 25% of all the UK's mail - over 4 billion items per year.
The company was a wholly owned subsidiary of the Dutch delivery company PostNL until October 2015, when a management buyout was completed and PostNL became a minority shareholder.