The research was conducted by the Unclaimed Assets Register (UAR). The managing director of UAR, Keith Hollender, says: "There can be various reasons why dividend cheques are not paid in, but in most cases, it is due to the fact that the company has the wrong address on its share register.
"That is not usually the company's fault - it is more likely that the shareholder has not notified it of a change of address."
Bankers have responded to UAR's findings by urging savers to take their dividends as direct transfers rather cheques. All this would require is filling out the direct credit mandate which about 80 per cent of shareholders are sent along with their dividend cheques.
Direct credits are the mirror image of direct debits. Instead of automatically taking money out of your account, they automatically put money in.
BACS, which runs the banks' automated clearing process, says 46 per cent of people claim they would like to get their dividends by direct credit, but only 30 per cent actually do so.
Mike Jeremy, a BACS spokesman, says: "The excitment of receiving a cheque is not the ideal context for people to concentrate on the dividend payment they are going to get in six months' time and how they prefer it to be paid."
Some of the shareholders surveyed by BACS see the cheque as proof positive that the dividend has been paid. But Mr Jeremy points out that each direct- credit payment generates a tax-credit voucher, sent through the post. This confirms the date and amount of the payment, together with details of the account into which it has been paid.
ProShare, a lobby group which works at promoting wider share ownership, is supporting BACS' call for more direct-credit payments.
Tony Hobman, who took over as ProShare's chief executive last Monday, says: "In principle, anything that ensures people get their dividends is a good thing, People have invested in the company paying the dividend - they own that company - and one of the benefits of ownership is that the company pays you a dividend. It is yours."
UAR plans to launch a service later this year allowing shareholders to find missing dividends from any number of companies with a single search. Mr Hollender hopes this search will cost shareholders no more than pounds 15 per person.
Mr Hollender says: "With the co-operation of the registrars, we should be able to create a database which will make it as easy as possible for shareholders to find out whether they are entitled to something. In many cases, the time when that is most appropriate is when someone dies, an executor is winding up the estate, and he has got to get in all the assets."
Until that service is up and running, your best bet of tracking down any dividends that you may be owed is via the company whose shares you own. Call the head office telephone number and ask for either the shareholder services department or the company secretary's office.
Yellow Pages, directory enquiries or the Stock Exchange Year Book in your local library are all possible starting points. Before picking up the phone, arm yourself with details of your shareholding and a note of any previous addresses where you have lived since buying the shares.
Mr Hobman says: "If you think you are owed dividends, or you are not sure, go and check with the company. They should have records which show whether you have any dividends that are not claimed and, in principle, you should be able to get that sorted out fairly quickly."
Beware of companies which write to you out of the blue saying they have discovered dividends or other assets belonging to you, and offering to tell you about them for a percentage fee. These companies' charges are high and the information they offer is often no more than you could uncover for yourself with an hour or two's work.
Dividends which remain unclaimed after 12 years revert to the company which issued them.
Unclaimed Assets Register: Bath & West Buildings, Lower Bristol Road, Bath BA2 3EG (01225 461006)