Whistl has ordered 41 double deck trailers which have been designed to handle containers for parcels as well as mail.
The trailers, worth some £2.5m are being built by Don Bur with maintenance and leasing provided by TIP.
Whistl chief Nick Wells said: “We are a growing business, not only in our core sector of business mail but also in our parcel services. The new trucks give us scalable and flexible infrastructure that can handle the increasing mix of items customers handover to us to process.”