Retailers will employ a computer model, currently being refined by the Euro Changeover Board of Ireland, to calculate their cash requirements for the period of the changeover to the euro, according to Mr David Croughan, chief economist with IBEC, the employers' confederation.

The model, which should be ready for use by the end of this month, will map their current transactions and project what their euro currency requirements in notes and coins will be, starting on January 1st, 2002.

The model has been developed in Ireland by a software company commissioned by the Changeover Board. "You block in all the transactions that take place over a period of a week - the bill, the amount tendered, the change given. The model automatically changes all that into euros, adds them all up and, on the assumption you use the highest amount of denomination possible, it calculates all your requirements and then has the ability to say, you therefore need so many packs of one euro, two euro, three or five or whatever."

Details were released in Dublin yesterday when IBEC and European Article Numbering (EAN) Ireland, the bar code people, introduced a code of practice and guidelines for retailers, together with a euro code logo, to ease the changeover to the currency.

Mr Croughan said the model was tested two months ago and there were problems. It was given to retailers who are testing it at the moment. "It will help them to calculate their euro cash requirements because they are going to have to put in orders to their banks in the not-too-distant future for currency. Ideally, they may well use it in the first week of next year so that they actually have a corresponding type of business, but it doesn't matter that much. What you can do is you can have an analysis on the number of transactions or the value of transactions and you can base it on a five-day period," he said.

Some 20 major retail groups, which are members of the IBEC/EAN Ireland Retail Working Group, have agreed to abide by the guidelines and display the logo in their stores.

The code and guidelines lay down minimum standards to ensure the conversion to euro is done accurately, that no advantage will be sought by the retailer and that in the event of error the consumer will not be disadvantaged.

They also stipulate that customers will be charged in euros only from January 1st, 2002 and that change will be given in euros only; that Irish pounds tendered during the period of dual currency will be converted using the six-digit conversion rate at no extra charge; that retailers will fulfil minimum standards on dual display of prices and undertake the necessary training of staff to help consumers make the changeover as smoothly as possible.

At the inception of the scheme in Dublin yesterday the Minister of State for Labour, Trade and Consumer Affairs, Mr Tom Kitt, said that like the Y2K situation, the changeover to the euro would work effectively only if there was proper awareness, preparation and training.

He added that inspectors from the office of the Director of Consumer Affairs would be involved in policing the changeover and ensure that consumers were not exploited "although I'm not convinced that is a real problem, I must say".

A similar guide has been developed for hotels and restaurants and negotiations are continuing with the Irish Petroleum Federation regarding forecourt shops.