And yet, as even the most modest sole trader is aware, in reality collecting revenues, paying bills and working out how much is left in profit is a tedious sine qua non to a company's core activity of supplying goods or services to its customers.

A small, but growing number of companies have recognised this, and taken the audacious step of outsourcing the entire finance function.

In a striking package deal, Accenture, the management and IT services group, took over the Aberdeen oil exploration finance departments of a trio of companies: British Petroleum Exploration, Elf, and Talisman.

It also grabbed attention with a deal to consolidate the finance back-office of Rhodia, the €7bn turnover French-based speciality chemicals group, in the Czech Republic, and a so-called "co-sourcing" agreement with the UK arm of travel group Thomas Cook to create a single shared service centre providing Thomas Cook's finance, IT and human resources administration.

The BBC, which had been working with Medas, a subsidiary of EDS, the IT services group, on financial transaction processing systems support and assistance in the implementation of a new software package, recently transferred its entire finance function to Medas. Meantime, BT, the UK telecoms group, saved £93m over seven years by outsourcing finance functions to Xansa.

Simon Tennant, a member of the management group at PA Consulting, says interest in outsourcing financial functions is growing as such ground-breaking deals catch the headlines. But, he says, companies need to examine their objectives carefully before deciding whether to take the outsourcing route.

"The big question, he says, is: 'What are the extra benefits that outsourcing can bring, rather than trying to sweat it out myself?'"

In his view, there are generally significant gains to be had in any organisation from centralising transactional functions, such as paying bills and processing invoices. "Typically, by moving towards shared services, you can gain benefits of the order of 30 per cent to 50 per cent of cost for that portion."

This is particularly true for large organisations that have grown piecemeal, with disparate systems and accounting offices in scattered locations. Simply putting all the transactions on one system enables a focus on buying from fewer, lower cost suppliers, and armed with the information revealed, buyers can obtain bigger discounts. One international electronics group achieved savings of €140m a year in this way, he says.

But a management with good skills in transformational re-organisation can reap the benefits without having to share the gains with an outsourced supplier, he adds.

However, for a management already stretched, outsourcing may be a good option. Similarly, outsourcing may prove more cost-effective where the outsourced service supplier can achieve economies of scale and spread fixed costs across several customers.

In some areas of the finance function, particularly those that involve a lot of tedious and repetitive data entry, the benefits of outsourcing to specialist providers are clear cut.

"Most treasury work is 70 to 80 per cent drudgery," says Declan Lynch, executive vice-president of Dublin-based JMH Treasury. "Back offices are involved in a day-to-day grind of reconciling bank accounts, tracking cash positions and monitoring cash-flow."

Most companies still do this with spread-sheets, held back by the cost of upgrading to an automated system. Typically, for the IT to link directly to a company's banks and monitor all transactions as they happen, costs £150,000 to £250,000 and a further 20 per cent in maintenance.

JMH Treasury, with 33 outsourcing clients paying anywhere from $3,000 to $40,000 a month, provides instead a web-based facility that tracks bank balances, records of ongoing foreign exchange transactions, derivatives contracts, current short-term debt positions and even inter-company loans.

In addition to eliminating capital investment, companies can cut their treasury operating costs. Metal processor Worthington Industries, which ran its old treasury system in parallel with the JMH Treasury system for two months to ensure its benefits, later reported that switching to the outsourced paperless system had saved 25 per cent in treasury operating costs.

Another area of the financial function where the benefits of outsourcing are widely recognised is in payroll and pensions processing.

Capita, a UK specialist supplier of such services, achieved revenues of £897m last year and processes the payrolls of 2m people employed by more than 450 companies and local authorities.

John Keegan, Capita's director of payroll services, says that for businesses with fewer than 2,000 employees, the biggest attraction is reduced risk.

With legislation and software changing frequently, and pay increasingly containing complex bonus and expenses elements, the best way to ensure accuracy, legal compliance and state-of-the-art delivery is to contract the work out to a specialist supplier, he says.

Larger organisations can benefit from the scale economies of an outside specialist and by avoiding lumpy investments in systems.

For similar reasons, many companies are looking at outside administration of employee share schemes and credit control. It is not simply a matter of cost-savings - using specialist providers in this way allows medium-sized companies and state bodies to deliver the quality of services to their own staff and to pensioners that can only be achieved through scale.