Forget cash. American Express, or any other plastic, definitely will not do nicely. Shopkeepers and tradesmen in west London may soon be accepting a new alternative bartering currency.

Hounslow council has become the first local authority to appoint a full-time development officer to set up a bartering economy. Its name has yet to be decided, but 'Poundslow' is a strong front-runner. An alternative is the 'Turpin', because of highwayman Dick Turpin's local associations.

Critics say such schemes are merely to dodge tax, particularly value-added tax. But the Inland Revenue's position is that as long as no-one makes a profit, then there is no need to pay tax.

Local Exchange and Trading Systems (Lets) have exploded in the past two years and the Hounslow currency will be the fourteenth in London. What sets it apart, however, is the council decision to pay a full-time co-ordinator, David Williams.

The schemes work by encouraging local people to exchange skills and services. Payment is evaluated in a unit of credit. Those with talents to trade join a printed directory offering anything from babysitting to decorating or car maintenance and quoting their Lets fee. They call it 'going local'.

So in Barnes it is the power of the Pond, in Brixton it is Bricks, Southwark trades in Pecks and Golden (based in the City) goes for Nuggets. The rough value is pounds 1 a Lets unit.

Mr Williams's first objective will be to visit other bartering communities in the capital. The second is to find on an acceptable name for the currency. The Turpin is a hot favourite but there is a council contingent that prefers the Poundslow.

Mr Williams plans to settle the debate with a competition inviting residents to suggest alternatives. Hounslow picked him after his success at establishing an alternative banking system - a credit union - in Hillingdon. People invest in their own co-operative bank. It makes no profit and gives loans at a lower rate than high street institutions.

The Hounslow brief includes setting up a similar system. Mr Williams said: 'I think we will get the whole thing kick-started with a charity auction of skills and services, then begin on the trade directory. It will provide a useful convenient service, help people who are short of cash, and foster community spirit.'

The Inland Revenue warned businesses that adopted the currency, either partially or wholly, to keep a careful record. 'Most people involved with Lets do not make enough profit out of it to be liable for tax. However, if, for example, a green-grocer started taking part of his payments in Poundslow credits and using them to trade other services, they might be eligible for tax. 'We do not really see Lets as a problem, the people who take part all appear on a register. Transactions tend to be recorded. It is easier to keep a check on these system than someone stuffing untaxed cash under their mattress.

Meanwhile, the appointment has caused excitement at the Wiltshire headquarters of Letslink UK - an organisation set up to co-ordinate schemes which sends out pounds 6.50 information packs.

National organiser Liz Shepherd said: 'Although local authorities have given backing to Lets schemes in the past, this is the first time we have heard of a full-time post being created to help people get started. It's very good news.'