Three branches of TSB, now part of the Lloyds group, also quoted different commission charges.Other complications are the effect of the different levels of charges and the fact that some institutions are better on different currencies. Thomas Cook, meanwhile, will often do special deals, waiving commission, for example, to win your business. Lloyds says all its branches have the same rates and charges, but we were quoted different exchange rates and commissions by four London branches in Camden, Islington, Oxford Street and Piccadilly, and by the bank's head office (the last of which we used for the table). Two different foreign exchange companies run the M&S bureaux de change, hence the two sets of rates in our table. Other branches with exchange facilities are in Bath, Edinburgh, Oxford, York, Canterbury and Windsor.

Many of these, though not all, offer commission-free currency sales. Banks and other bureau de change operations generally make a charge.The table is just a snapshot - the comparisons will not necessarily last (let alone the rates) - but it is noteworthy that in general terms the high-street banks and Thomas Cook come out poorly. Lloyds is the obvious exception.It may even be worth shopping around at different branches of the same institution. You can get more than 2 per cent more foreign currency for your pounds from M&S, compared with the worst of the banks and other well-known bureau de change operations. For the three big holiday currencies surveyed (see table), if you are changing pounds 500 this difference could be worth an extra 19 US dollars, 85 French francs or 30,000 Italian lire.The retailer has nine branches with bureaux de change, three of which are in London - at Marble Arch, the Pantheon store on Oxford Street close to Oxford Circus, and in Kensington. Cards are vital for confirming your credit status, and you'll have to present some plastic before you are allowed to set foot in a hotel bedroom And if you try to hire a car without a card, forget it.. Marks & Spencer comes out best for buying foreign currency from a survey by the Independent on Sunday.

Credit and debit cards have also suffered in the past from being "cloned". This is the practice whereby details stored on the magnetic strip are copied while the card is out of your sight, perhaps in a restaurant, to be used to debit your account subsequently.Your travel agent should be able to advise on the best currencies in which to denominate traveller's cheques. Sterling is often as good as any for much of Europe, although American Express differs from some providers in specifically recommending you take the currency of the country you are heading for. Certainly, the dollar is king in the US; turn up with sterling and expect laughter.In fact, in the US, dollar traveller's cheques are accepted as cash in shops and restaurants, so the hassle of turning them into dollar bills can be largely removed The US is also the land of plastic. Consumers can only obtain TravelMoney cards through Bank of Scotland at the moment, although the plan is to make them more widely available.But for now the knowledge that traveller's cheques cannot disappear into a wall thousands of miles from home may be enough to persuade many people that commission of 1 per cent to 1.5 per cent is a price worth paying for security. With card purchases there is no commission and you will normally get a "better than tourist" exchange rate - closer to that quoted in international money markets.There are innovations which combine the benefits of plastic's superior exchange rates with the "budgeting" aspects of traveller's cheques.Visa is piloting TravelMoney, a pre-paid card which is "loaded" with as much money as you require - rather like a phone card - and can be used to withdraw cash at any of Visa's 250,000 holes in the wall around the world.