Whistl UK posted a loss in the year it begin a nationwide roll-out of its own final mile delivery network.

Its annual accounts for the year ended 31 December 2013 show that the company recorded a £8.1m pre-tax loss, compared to a pre-tax profit of £5.7m the previous year.

Whistl declined to comment on the results, but financial reports published at Companies House said turnover grew “in line with anticipated growth of the company”. Its turnover for the year increased 3.6% to £574.9m (2012: £554.5m).

It carried over 3.9 billion items during the year, while parcel volumes grew by a third. The report also revealed that it won new customers in the retail and e-commerce sectors and it was able to grow its international business.

“With a customer base of more than 8,000 customers and opportunities within the small and medium-sized enterprise sector, a strong opportunity for growth remains within the packets and parcels sector and in e-commerce,” the report said.

In 2013 it began increasing the spread of its final mile delivery network, launching the service in south west London and Manchester. By the end of 2013 it had delivered to 1.2m addresses out of 23 depots.

Parent company Post NL entered into a joint venture with Lloyds Development Capital (LDC) in December 2013 to enable the roll-out of a nationwide final mile service. The deal includes a funding package from LDC and Royal Bank of Scotland.