The 46-year-old financial journalist chatted money with ITV presenters Susannah Reid and Ben Shepherd.
Martin revealed that the top 0 per cent debt shift deal ends Friday.
He said: “Anyone paying interest on existing credit or store cards needs to sit up and take note.
“A balance transfer is where you get a new card that pays off the debts on old cards for you – so you owe it instead but at a lower rate, usually at 0 per cent.
“This means all your repayments clear the actual debt rather than covering the interest – so you’re debt free quicker.”
Martin revealed that until Friday Britons can get up to 32 months at 0 per cent with HSBC.
He said: “It does charge a 1.4 per cent fee (£5 minimum), but it’ll credit £25 into your account if you transfer £300 or more in the first 60 days.
“So, if you’ve under £1,750 to shift the cashback effectively cancels out the fee – making it better than the longest fee-free card available – or you may even actually be up.”
Yet if you are balance transferring, Martin has some golden rules to follow:
1. The same brands have many similar cards, check you’re applying for the right one.
2. Repay at least the monthly minimum or the bank can end the 0 per cent deal.
3. Clear the card in full by the end of the deal or the rate rockets to 19.9 per cent rep APR.
4. Never withdraw cash or spend on the card as it’s not at the 0 per cent rate.
Martin also added that it is important to check you will be accepted.
You can find that out using Martin’s free ‘Balance transfer eligibility calculator’ tool – it shows which top cards you are most likely to get, without impacting your credit worthiness.
He said: “The real issue at the moment though is that deals are getting much worse, in fact a year ago you could get 10 months longer 0 per cent than you can now.
“And another top deal is ending, without anything close looking to replace it.”
Martin Lewis recently revealed the ISA which gives you £1,000 per year free.