Newspapers are filled with hundreds of small ads selling everything from coffee grinders to cars.

Private sellers also use car boot sales and postcards in shop windows to attract potential buyers.

However, you don't have the same rights when buying privately as you would when you deal with traders. It is illegal to represent yourself as a private seller if you are not, and consumers should be aware that some unscrupulous traders pass themselves off as private individuals in order to avoid their legal obligations.

When you buy goods privately they must be as described, but the other rules about satisfactory quality and fitness for purpose don't apply.

So how can you identify which of the adverts are genuinely from a private seller? Although there is no sure, fast method, there are some common things to look out for. For instance, if the same telephone number appears in several ads or the same ad appears regularly then this may indicate traders disguising themselves as private sellers. Avoid ads which only give mobile telephone numbers - you need details of the seller in order to be able to enforce your rights if things go wrong.

At car boot sales some giveaway signs that individuals may not be what they seem are if they offer many copies of the same item or very cheap branded items. These may be stolen or counterfeit.

It is particularly risky to buy a car privately. It will invariably be cheaper than buying from a dealer but there are pitfalls to be aware of. Remember the car only has to be as described, but that it may prove to be stolen or "clocked", it may still belong to a finance company, it may be an insurance write-off, or even two cars welded together to create a new one. In cases such as these, you could lose all your money.

Always check the seller's identity by asking for proof of name and address and be wary of sellers who want to meet you anywhere other than their home. Also ask to see the V5 (the registration document) and check that it is unaltered and carries the same address as the seller's ID. Check the number plate matches the information on the V5 and verify that the vehicle identification number also matches the document.

You can check if a car is clear of any outstanding finance deals by contacting companies that research the car's history for you. Don't forget to obtain the MOT certificate and service documents as these can help you verify if the mileage is accurate.

But don't be put off using small ads - now you know what to look for there are real bargains to be had.

For further information on buying privately or any other consumer matter please telephone City of York Trading Standards on 551562 to obtain advice or make an appointment to see an adviser. Our website address is www.york.gov.uk/business/tradingstandards

Updated: 08:58 Thursday, September 25, 2003