Bought a TV recently? Then the TV licence people know about it...

UK retailers are legally obliged to hand over the names and addresses of anyone who buys a television to the TV licensing authority.

This isn't exactly anything new - indeed, it's covered by legislation first drawn up 35 years ago.

But it's not widely known that the organisation which administers the licence scheme on behalf of the BBC, TV Licensing, uses the data to check if the purchaser has a TV licence.

If there's no match between its records and the details supplied by the retailer, the company will quickly send the customer a letter informing them that, as the owner of a new TV, they must have a licence.

The Data Protection Act (DPA) places strict limits on what 'data controllers' can and cannot do with their customers' records. Normally it would be illegal to pass on such information to any third party without the express consent of the customer.

But the Wireless Telegraphy Act (1967) requires "any dealer who sells or rents TV receiving equipment (whether the equipment is new or second-hand) to notify TV Licensing within 28 days of each transaction, giving full details of the buyer or renter".

This means that the DPA does not apply in such cases.

silicon.com looked into the matter after one reader got in touch having recently bought a TV from Argos.co.uk. He was extremely surprised to receive a letter from TV Licensing soon after, telling him that he didn't have a licence and asking him to buy one. (He did in fact have a licence - but it was in his mother's name.)

There is no specific mention of this practice on the Argos site, although it does say in its privacy policy that it will pass on customer information "if we have a duty to do so or if the law allows us to do so".

Simon White, a solicitor in the Trade and Innovation Group at law firm Browne Jacobson, said: "There's no legal obligation for e-tailers to explicitly inform their customers that their data will be passed to the TV licensing authorities. In fact, they're actually complying with the law by doing so. But it might be good practice for all retailers selling TVs and videos to let their customers know that this will happen. This would then comply with the spirit of the Data Protection Act 1998. It's especially important for e-tailers to make the buying experience as transparent as possible."

Argos certainly cannot be accused of doing anything wrong. But ironically, a lot of TV retailers probably are, but for a very different reason: not passing on their customers' names and addresses. The National Audit Office (NAO) believes the BBC missed out on £8m worth of potential licence revenue in 2000/2001 as retailers failed to notify it of up to 40 per cent of TV sales.

However, TV Licensing itself disputes that figure. A spokesman told silicon.com: "The NAO is not comparing like with like. We believe we are receiving the majority of the notifications and 40 per cent is an over-estimate, because it does not take account of multiple sales at a single address, nor of VCR sales, about which dealers do not need to notify us." He added: "We rely on dealers to comply with their legal obligations but we also take steps to publicise dealers' obligations through the trade press and we prosecute dealers wherever we discover that they have failed to carry out their legal obligations. In the last 18 months, Argos, Sainsbury and Big W are among those which have been successfully prosecuted."

So next time you buy a TV - assuming your local retailer is 100 per cent legit - expect a letter from TV Licensing. But only if you've not got a licence or it's in someone else's name. You have been warned.