Thousands of shoppers took advantage of the long Bank Holiday weekend to buy new “must-have” gadgets for the home, encouraged by falling prices on the high sreet.

But insurance experts say that the boom in sales of high-tech electrical items, such as flat-screen TVs, means that many of the most valuable possesions in the home are not adequately insured. A quarter of a million contents claims are rejected each year because homeowners do not have sufficient cover, according to Abbey.

Hayley Parsons, of GoCompare.com, the price comparison website, says: “Modern gadgets, such as laptops and sound systems, can be worth thousands of pounds, but many insurance policies have limits on the values of the individual items that you can claim. It is vital to inform your insurer when you make a new purchase and check your level of cover, or your risk being uninsured.”

Home contents insurance usually covers your household items and personal belongings up to about £40,000, and individual items up to between £750 and £1,000. If you have single possessions worth more than £750, you should register the details with your insurance company.

Lloyd Wilson, of Abbey Insurance, says: “We recommend that people review their home contents insurance every six months to make sure that all their valued items and heirlooms are fully covered.”

But the good news for people looking to increase their level of cover is that the home insurance market is very competitive and some great deals are available. The cheapest deal for annual contents cover of £40,000 on a three-bedroom, semi-detached home in South Wales is £55.59, from Homequote Direct, according to GoCompare. If you include one high-value item on your policy, the cheapest price on the market jumps to £99.62, from Swinton. This includes cover for accidental damage.

If you have two expensive items insured for £6,500, the cheapest premium available rises to £147.50, from esure. Debra Williams, of Confused.com, another comparison website, confirms that it is worth shopping around every time you add valuable items to your policy.

It is not just household goods that need to be considered. Expensive items of jewellery also need to be registered on your home contents cover. For example, research suggests that almost half of all engagement rings are not insured. Insurance experts also give warning that there has been a steep rise in gold prices, a by-product of the credit crunch, so items such as gold jewellery could be worth more than you expect.

Updating your cover to include new jewellery or your latest portable gadget, such as an iPod or laptop computer, is particularly important if you have personal possessions insurance, which covers you for loses away from your home. Andrew Lowe, of Direct Line, says that homeowners should avoid being underinsured by remembering to register items for their replacement value rather than their resale value, which will decrease over time.

If you are fortunate enough to have acquired a number of valuable items at home, it could be worth considering a specialist insurer. Hiscox, for example, provides buildings and contents cover for homeowners with contents worth £50,000 or more.

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