Apparently no matter how hard they try, our credit companies just can't shake a lucrative card customer. New research exclusive to Money shows that in the past five, price-gouging years, a staggering 77 per cent of credit card holders have been either too "lazy" or too "loyal" to change cards. The creditcardfinder.com.au study of more than 1000 Aussies implies that card companies have clung on to more than 12 million credit accounts we probably should have ditched. Despite their extreme interest rate intransigence – while official interest rates are now 1.75 per cent, card providers have held average rates at a dreadful 17 per cent – almost two-thirds (62 per cent) of respondents said they are "happy" with their card. It's probably no surprise that another 17 per cent of those surveyed think switching is too much hassle; one in eight (12 per cent) said the reason they hadn't shopped around was "all cards were the same".

But here's the really shocking thing. Based on our total outstanding debt at the average rate, Australians are now wasting an estimated $4.3 billion a year in interest. Yep, $4.3 billion. Today's cheapest card charges not 17 per cent but only 7.99 per cent – it's Quay Credit Union's Visa. But the $4.3 billion potential saving comes from the now 160 cards, according to finder.com.au, that allow you to transfer a balance and pay absolutely no interest on it for an introductory period. One year ago, there were only 144 such deals. Providers have been increasing the length of the 0 per cent periods they offer to lure customers too – from an average of 10.9 months in June last year to 12.9 today.

Then, there were only 62 products with interest-free periods of a year or more. Now there are 111. Twenty of these balance transfer deals even come with a $0 annual fee (just watch out for an average purchase rate of nearly 18 per cent and a so-called balance transfer fee that could negate savings). But note you have to "change allegiance"; if you're an existing customer, you won't be able to access these sweet 'honeymoon' deals. So is it fear of nuking our credit rating that prevents us from taking up the proliferation of offers to repay our debts for free and cut up our old expensive cards? I don't think so. Besides, it's easily avoided. Two applications for balance transfers should have very little effect; go for a third, however, and a provider will logically conclude you're either working the system or have a problem with debt.

Finder's survey reveals 5 per cent of cardholders have cannily switched twice in the past five years while 1 per cent, or 164,418 people, have switched a rating-wrecking five times. It's key not to collect cards, but to cut them up – this goes on your credit report and shows you are in control, not out of it. And just two balance transfers now buys you more than two years to knock off your revolving credit card debt, which the Reserve Bank says is an average of $1984, once and for all. That would take only $83 a month. So what's stopping you? The tricks to a transfer

How to make sure you come out ahead: 1.Don't use cards for new spending (or withdrawing cash) – it will attract a nasty interest rate, from day one. 2.Ditch the card immediately if you have remaining debt at the end of the interest-free period – it will usually attract an even higher rate than purchases. 3.Cut up old credit cards to remove the temptation to get yourself in a fresh debt hole (and protect your credit rating). Nicole Pedersen-McKinnon is a commentator and educator who delivers Smart Money Start, fun financial literacy, in high schools around Australia. themoneymentorway.com