ONE of the fastest-growing businesses of its kind in Britain has moved into new headquarters in Hampshire.

Liquid Friday has leased the top floor of three-storey Port House, which overlooks Port Solent marina, near Portchester.

The company, with a £63m turnover, is a payroll services provider for more than 2,500 UK-based contractors and freelancers from all sectors.

They include building trades, recruiters, locum doctors, teachers, engineers, vets and IT.

Liquid Friday's turnover includes the turnover of its customers.

The 30-strong company, led by chief executive Phillip Venn, employs contractors, locums and temporary workers, taking care of tax, including business expenses to offset the amount of tax owed, and National Insurance deductions.

Its sister company Boox, with a 50-strong team of accountants operating at the premises, was set up from scratch three years ago by Phillip to meet a gap in the market.

The business provides online accounting services so Boox's 4,000-plus customers can see their tax obligations and pay breakdowns in real-time, with dedicated points of contact. Nearly £2m was invested in the start-up, including in an highly successful app.

Liquid Friday, named after a tongue-in-cheek expression for contractors celebrating pay-day with drinks, relocated from commercial units in Fratton, Portsmouth, having outgrown the business space.

Under Philip's leadership, Liquid Friday was named the 22nd and 30th fastest-growing private business in the UK in 2011 and 2012 in the Virgin Sunday Times Fastrack 100 Awards.

In 2009, the company, then with two staff, had operated out of Portsmouth Technopole, the serviced offices centre by the M275, as an early-stage business with 80 users and a £0.9m turnover.

Port House was recently refurbished to high standards by freeholder Premier Marinas, with Liquid Friday carrying out a funky fit-out with a nautical theme.

Hughes Ellard acted for Premier Marinas, the freeholder of Port House and operator of the marina and boatyard.

Phillip said: "Port House meets our high standards for a headquarter building in which to continue to grow both Liquid Friday and Boox.

"The demand for our services from customers is phenomenal - they feel reassured by our best-practice compliance culture and easy-to-understand and accessible accountancy.

"We anticipate filling our top floor, from the current 85 staff, to a maximum-capacity 120 sooner rather than later, creating both jobs and inward investment locally."

He added: "We're grateful to Hughes Ellard for facilitating the property deal - the firm acted to the letter, freeing us up to focus on what we do best."

Russell Mogridge, Hughes Ellard's business space director for the Solent Corridor, said: "With the arrival of Liquid Friday and Boox, and the ground-floor cafe, bar and meeting rooms for hire, which is run by local company Vanilla Gourmet Catering, Port House is now two-thirds full.

"Given the excellent economic conditions in the UK, fuelling employment growth, we expect the second floor, which is 6,500 sq ft, to become occupied in the near future.

"The office location is second-to-none, given the waterside location, ample parking and motorway access, plus Port Solent's attractions on the doorstep, such as the restaurants, bars, cinema and health club."

The first floor has a quoting rent of £17 per sq ft.

Phillip said: "The growth of Liquid Friday and Boox is also the result of record self-employment in the UK - it is the highest at any point over the past 40 years since data was collected."

According to latest figures by the Office For National Statistics, 4.6 million people were self-employed in their main job last year, accounting for 15% of those in work.

There were also a further 356,000 employees with a second job who were self-employed.

The top roles for self-employed, where the average age is 47: construction and building trades (167,000), followed by taxi and cab drivers and chauffers (166,000) and carpenters and joiners (144,000).

Women made up just under one third of the self-employed, at 1.4 million, an increase of 34% since 2009. There were 3.1m self-employed men, a rise of 15% over the same time.

Hughes Ellard is the joint letting agent of Port House with JLL.