A Martin masterclass... IN FULL
7 ways to play your (credit) cards right: make £100s, get 'free' flights & airport lounges, cheap euros & more

Ends today. Free £50 M&S vouchers credit card deal

There's nowt more fun than neutering a credit card. Don't worry, this isn't a cruel sport, it's just a way to stop 'em from being debt cards and instead turn them into the perfect way to pay, with powerful perks at no cost.

And neutering one is easy. Just set up a direct debit to pay the card off IN FULL (listen to that in its full glory) each month, so there's no interest. Then use it for spending, and it's effectively a debit card, as long as you don't bust the credit limit.

Things have just improved for credit card users

On 13 Jan new rules stopped retailers levying extra fees for those paying with personal credit cards. While a few still naughtily haven't changed, most charges are now consigned to history. Some firms have frustratingly replaced them with a charge for all, but even then it means there's no longer a premium to pay via credit card.

So here are my 7 current top IN FULL perks followed by a Q&A...

1.  Ends TODAY: Free £50+ M&S vouchers. Accepted new cardholders (use our elig ibility calc to see your acceptance chances) who apply via our M&S Bank* link by 11.59pm Wed get a free £50+ to spend in its stores on almost anything (incl clothes and food). It's split into three...

(i) £20 in M&S pts. Just spend anything anywhere within 90 days to get this.
(ii) £30 M&S vch. Spend £100+ anywhere by 31 Mar.  
(iii) Extra £5 M&S vch. You're sent a coupon with the card. Scan it when you buy almost anything at M&S and you're due another £5 of points.

So in a nutshell, spend £100 anywhere and you get £50; spend any of that at M&S and you can get £55. Just ensure you never withdraw cash and repay the card IN FULL to avoid the 18.9% rep APR interest. If you don't want the ongoing M&S pts, get the vouchers then cancel it. More help and options in Credit Card Rewards (APR Examples).

2. Free £100 Amazon voucher or British Airways Europe return flight + 2 airport lounge passes. Spend £2,000+ in the first 3mths on the Amex Rewards Gold* (use our eligibility calc to see your acceptance chances) to get freebies. It sounds a lot, but £700/mth isn't that big for many families.

You get 20,000 bonus Membership Rewards pts - redeemable for a £100 Amazon/Boots/M&S gift card or convertible to enough Avios points for a European BA return (though you pay taxes and charges). You also get two free worldwide airport lounge visits per year (and ongoing points).

This card is a charge card, not a credit card, meaning you MUST pay IN FULL... Missed repayments cost £12 and mean a credit file black mark.

WARNING: There's a £140 annual fee after the first year - remember to cancel if you don't want to pay it.

If you won't spend that much, the Amex Rewards* credit card (eligibility calc) gives 10,000 bonus pts (equiv to a £50 vch) for a lower £1,000+ spend in 3mths. If you don't repay IN FULL every month, it's 22.9% rep APR.

3. Earn 5% cashback on all spending, 'I get £200-£300/yr'.  Rather than one-off perks, cashback credit cards pay you every time you spend on them. So use one for all spending, repaying IN FULL, replacing cash, cheques and debit cards - and you earn (never withdraw cash though).

Some make big bucks, incl Christine: "@MartinSLewis £200-£300 per year cashback for the last 15yrs or so with Amex #happybunny."

The no-fee Amex Everyday* (eligibility calc) gives accepted new cardholders 5% cashback (max £100) for 3mths then up to 1% after. You must spend at least £3k/yr to get any cashback. If you'll spend £9,000+ a year, the Amex Platinum* (eligibility calc) pays slightly more, even after its £25 annual fee. Always be sure to repay IN FULL, or you'll pay the 22.9% rep APR which'll dwarf the cashback gain.

The easier-to-get Aqua Reward* Mastercard (use our eligibility calc to see your acceptance chances) pays 0.5% cashback on all spending (max £100/yr) and is accepted in more places (it's also good for spending overseas - as in point 5). Always pay IN FULL to avoid the horrible 34.9% rep APR. Full info and options in Top Cashback Cards (APR Examples).

4. New York City business-class return (big spenders only). I wrote this £500 for 2 biz-class tickets to NYC blog in 2010, and while of course prices have since risen, the principle of huge savings still stands. It's all about credit cards where you earn frequent flyer miles for spending, and it can be far more lucrative than cashback cards - getting bigger spenders who collect over a few years high-end flights worldwide.

The no-fee BA Amex* (eligibility calc) gives 1 Avios point per £1 spent, plus 5,000 extra when you spend £1,000+ within the first 3mths. For big spenders, put £20,000+ on it (great if you pay then reclaim expenses) and you get a 'free' companion ticket, meaning whatever ticket you redeem in points, even first-class, you get a second 'free' (you still pay taxes). You've one year to claim the flight. Of course, do repay IN FULL each month to avoid the 22.9% rep APR.

Or, if you'll definitely use it for biz/first-class, then for a £195 annual fee, the BA Premium Plus Amex* (eligibility calc) gives a higher 1.5 Avios per £1 spent, plus 25,000 extra if you spend £3,000+ within the first 3mths. Most importantly it also offers a 'free' companion ticket but at a much lower &poun d;10,000+ spending trigger (and you've 2yrs to claim the flight). Fail to repay IN FULL and it's 22.9% interest (not including the £195 fee).

Warning: Flights at the right time can be tricky to find, so it's best for those with flexibility to travel when flights are available.

Virgin has similar cards but they're not available to new cardholders at the moment. Full info in Airline Credit Cards (APR Examples).

5. Near-perfect exchange rates in every country + £20 cashback. A few specialist credit cards give near-perfect exchange rates when you spend on them abroad. So provided you pay off (you guessed it) IN FULL, it's the no-hassle way to save big bucks on your, er, big bucks (and euros, colons etc).

And right now one of the top cards, Halifax Clarity* (use our eligibility calc to see if you'll be accepted) gives newbies £20 if they spend in a foreign currency by 31 Mar (incl online, eg, hotel bookings). Again, repay IN FULL to avoid 18.9% rep APR. For more on this see our Top Travel Cards guide.

6. Get paid £40 to (re)build your creditworthiness. To get credit you need to have a history of being a good credit citizen. If yours is bad, or doesn't exist, a credit (re)builder card can help.

Just do £50-£100/mth of normal spending on one, repay on time IN FULL and within 6mths to 1yr your score should improve. To see which you've the best acceptance chances for, use our eligibility calculator.

Apply by 7 Feb and new Barclaycard Initial* custs will get £10 credited to their account every 3mths for a year (so max £40). You need to spend on it at least once within those periods, repay at least the min each month, and stay within your credit limit. There's 3mths 0% on spending, but it's a horrid 34.9% rep APR after that if you fail to repay IN FULL. 

7. ALL CREDIT CARDS: Free Section 75 protection. Pay on a credit card (not debit cards, not cash, not charge cards - see pt 2, not cheques) for an item costing £100 to £30,000 and it's normally covered by Section 75 laws, meaning the card firm's JOINTLY liable with the retailer if something goes wrong.

The obvious benefit is if you order something and the retailer goes bust, you can get your money back from the card firm. But actually the joint liability means anything you can complain to a retailer about, you can choose instead to go to the card firm about.

Eg, if you bought a posh handbag in New York, and discover a fault, you can ask the card firm to sort rather than 'going back' to the shop.

Plus, staggeringly, the card provider's liable for the ENTIRE amount, even if you just pay 1p on the card. See 'I got £23k back on my kitchen after paying £200 credit card deposit'. That's why I do all major purchases on a credit card. Full S75 help.

Q. Does this hurt my credit score? Every credit application leaves a mark on your credit report for a year. Not a biggie unless you do lots in a short time. Yet if you're about to make an important credit application within the next few months (eg, for a mortgage), I'd hold off. Full help in the free MSE Credit Club.

Q. How many cards can I have? Each lender scores differently, but over time many good credit scorers do have 5, 6 or 7 credit cards. Just ensure you spread out applications, and with this number it's probably (this is art not science) worth cancelling old unused cards. See Should you cancel old credit cards?

Q. I don't trust myself, should I do this? No. Credit cards are like fire - used right they're a great tool, used wrong they burn. If you may not pay off in full, it isn't worth it, play safe. 

Q. Why IN FULL, why not just 'most of it'? If you pay off credit card spending in full, there's no interest. If you miss even just 1p, you pay interest on the WHOLE amount (not just what's left) for the month.

Q. What if I forget to make a repayment? You'll usually be given a charge, and have a mark on your credit report. Hence why I say set up a direct debit to repay in full. 

Q. Can I get extra cashback from cashback sites? Sometimes, yes - see our Top Cashback Sites guide for full info.

'£40,000 PPI back' and how to do a weekly shop for £2
The Martin Lewis Money Show, ITV, 8pm Monday night 

"An amazing 3.8m watched my 'Help to Buy ISA v LISA' show on Monday (watch again online or the Sun morning ITV repeat) - thank you. Next Mon: 1) How to check if you're owed PPI, including the new rule that means even millions who were rejected are now owed. 2) How to do a weekly shop for £2/person. Do watch or set your Betamax."