CASH is King ... or so they say. I’m afraid I disagree. It has advantages for budgeting and haggling. But when it comes to spending or making savings safer, cash comes a distant second place.

Here are my 10 need-to-knows.

1. Don’t stash cash under the mattress — it’s only covered

for £750 A recent tweet from one of my Twitter followers says it all.

“My granddad just passed away. Found £22,000 in his flat.

£3k in various jacket pockets and drawers, £19k in a suitcase.”

Granddad didn’t only lose interest, he was also poorly protected.

Most home insurance only covers up to a max £750 cash and require a receipt/bank statement as proof.

It’s not just a financial issue. As fireman@ddukeofdarkness responded on twitter, “Money under the mattress makes a nice accelerant in house fires for us to deal with.”

2. Save in a UK bank and you’re covered for up to £85,000

Put money in a UK-registered savings account or cash ISA rather than under the mattress and, if the bank collapses, the Government promises to pay out up to £85,000 per person, per financial institution.

This excludes ING Direct which is Dutch regulated and protected.

3. Urgent. Save at four per cent AER TAX-FREE

This year’s cash ISA allowance closes on April 5.

If you don’t use it, you lose it. A cash ISA is a savings account you can put up to £5,340 a year in, where interest is tax-free year after year-after-year.

If you’re willing to lock cash away, 4.5 per cent is possible. The top easy access deals are about 3.5 per cent, though this includes an introductory bonus, so diarise to transfer and switch in a year.

Updated best buys at www.moneysavingexpert.com/cashISAs

4. Pay 1p on a credit card to protect a £5,000 purchase

Another warning inspired by a twitter question: “My 86-year-old dad put a £120 deposit at a restaurant (he doesn’t believe in plastic). It’s gone into administration, what can he do?”

Sadly, the answer is ‘not much’.

While many find it counterintuitive, paying by plastic is safer.

Buy goods for £100-£30,000 on a credit card, and under ‘Section 75’ laws, the card firm’s jointly liable, so you can claim a refund from it if there’s a problem.

The gobsmacking fact is even if you pay just 1p by credit card for a £5,000 kitchen, the card company’s liable for the whole amount.

Though repay the card in full to avoid interest.

If you don’t like credit cards, debit cards offer a lesser non-legal protection called chargeback, which is an okay last resort.

5. Get paid £100s to spend on plastic too

Capital One’s World Mastercard pays a huge five per cent back (£5 per £100) on all spending for the first three months, up to £100 cashback.

Then it’s a tiered rate up to 1.25 per cent. Not only do you get Section 75 protection, but get paid when you spend.

Only do this if you set up a direct debit to repay in full each month, or the 19.9 per cent representative APR dwarves the gain.

6. Beware if you opened savings over a year ago

Check your current rate.

It’s likely to be paltry, often less than one per cent, so ditch and switch.

If your ISA is used up, the top easy access accounts pay around three per cent. If you can lock money away for longer, four per cent is possible.

Deals change – see www.moneysavingexpert.com/topsavings

7. For safety and high returns, clear your debts

If you had £1,000 stashed in a top savings account paying three per cent and the same amount on a credit card charging you 18 per cent APR, by repaying the debt you’d be £150 a year better off (more after tax).

If you’re thinking, “but I need the cash in the bank for emergencies”, keep a credit card (ie, roof falls in, not need new haircut).

Meanwhile, you save hugely on interest.

8. Save large amounts in 100 per cent safety

If you’ve big savings, perhaps from a house sale, the highest safe return comes from spreading £85,000 chunks across top savings accounts at different UK regulated institutions.

See www.mse.me/safesavings for what counts as ‘different institutions’ .

Want it all in one place? The only route’s NS&I’s Direct Saver, but the rate’s a low 1.5 per cent AER.

9. Don’t store cash in current accounts

If you’ve £1,000s in a current account and it usually pays paltry interest, get a high interest savings account instead.

10. Shops needn’t accept your cash just because it’s legal tender

You may be surprised that no bank notes are legal tender in Scotland. In England and Wales, only Bank of England notes are.

Though, frankly, legal tender is meaningless in day-to-day life.

Anyone can choose to accept or refuse any payment.

Legal tender means it can’t be refused as settlement of court-ordered debt.

Bulk buy your postage

BEAT HUGE stamp price hike From April 30 1st class lettersized stamps will cost 60p (now 46p), 2nd class 50p (36p).

Yet provided they say ‘1st’ or ‘2nd’ rather than a price, they’re effectively inflation-proofed, as they’re still valid after prices go up.

So bulk-buy now, even for Christmas card sending for 2015, and you’re quids in.

Once prices go up, they’re very unlikely to ever come down.

Until April 10, Superdrug is offering books of six and 12 first class stamps at five per cent off.