15 vital facts you should know about your money From who to call if your card is pinched to the baffling code that could save you a fortune in tax, Sam Dunn explains how you can save hundreds. Every year, the taxman sends out millions of codes comprising a series of letters and numbers that tell your employer or pension provider how much tax to deduct from your income. Many people who receive the code ignore it, don't understand it, or fail to question it. This can be a terrible mistake. If your code is wrong, you'll end up paying too little or too much tax - and HM Revenue & Customs will hold you responsible for this. You could be landed with a bill for hundreds, and sometimes thousands, of pounds. So find out what codes your employer is using and try to understand what it means. You can find a list of all the most common ones and what they mean at: hmrc.gov.uk/incometax/codes-basics.htm. If you're still struggling, call HMRC. Save money: From understanding your tax code to office perks, we explain how you can save hundreds It's that gut-wrenching moment when the cash machine swallows your debit card, or you suddenly realise it's not in your purse or wallet any more. You urgently need to call your bank to stop any transactions - but the number you need is printed on the card you no longer have. So write it down somewhere safe, and log it in your mobile phone. That way, if disaster strikes, you'll be able to block payments immediately. You may think that if you underestimate the value of all your jewellery, electronics, TVs and valuables then all that will happen if, for example, your house is flooded, is that you won't get a full insurance payout. However, under a little-known rule, you could get nothing. This is known as being under-insured. It's vital you know precisely how much your valuables are worth - and give a proper assessment on your home insurance form. If your insurer discovers the value of your possessions is greater than you stated when you took out the policy, then they could refuse to pay out and simply refund your premiums. Some will give a percentage of your losses. Thoroughly assess the cost of replacing all your contents on a new-for-old basis, including smaller items, such as clothes and kitchenware. We guarantee they'll be worth more than you think. Good or bad news? Knowing your credit rating is vital as it will be checked even before you buy a mobile phone Your credit rating is an assessment by banks and building societies of how good a customer you are to lend to. It affects your daily life: it's impossible to get a mortgage, bank account, credit card, loan or even mobile phone without it being checked. Even though it's vital you know what your rating is, most people have still never checked theirs. If it does hold a nasty surprise, at least you'll be able to do something about it. Specialist agencies such as Experian and Equifax hold all your financial information. By law, they must give you your credit report for £2 by post, or £4 if you register over the phone. Rival firm Callcredit offers a free service called Noddle at noddle.co.uk. The date at which people can claim their state pension - currently worth £110.15 a week - is changing all the time. Today it is 65 for men and 61 and seven months for women. By 2018, the women's state pension age will be 65. After then, retirement age for both sexes will rise to 66 by 2020, and to 67 by 2028. Following this, the age will increase with life expectancy. To further complicate matters, a new flat rate of £145.50 a week in today's money will be given to anyone who hits state pension age after April 6, 2016. So, it really matters to know when you will be able to claim. Your current predicted date is at gov.uk/calculate-state-pension. Or call the Pension Service on 0845 606 0265. Most travellers are aware that there is some kind of fee for spending or withdrawing cash when they are on holiday. But few realise the layer upon layer of charges that exist - and how eye-watering the real cost can be. You could be hit with paying an extra 2.5 per cent for using a cash machine; 2.75 per cent for the so-called currency "load" fee; and a set fee of £1.50 for using your card in a store. In total, it can mean a £100 cash withdrawal will actually cost you £105.25. Look up what you're paying by pulling up the fees and rates section of the bank's terms and conditions. Then sign up for a card with lower or free withdrawals. Halifax Clarity credit card is fee-free for overseas transactions. Shops love selling warranties - they are a great way of making a little extra profit. But many only duplicate the laws that already protect you if something you buy is faulty. Another trick stores pull is to wash their hands of a complaint, and tell you to contact the manufacturer. The law is clear - and it pays to know it. In the first six months after sale, it's up to the shops to prove the item wasn't faulty, and they must deal with the problem themselves - not fob you off to the maker. Swot up on the Sale of Goods Act 1979 and the Supply of Goods and Services Act 1982. There's a useful guide at thisismoney.co.uk/consumer. How much your loved ones would need should you suddenly die is a key question faced by many families. But many people overlook the help that their employers give full-time staff members with death-in-service benefits. These payments are largely tax-free and typically three or four times your annual salary. It's paid to whoever you nominate - usually a partner or children. You'll only qualify for it at some companies if you are in their pension scheme. Before you take life insurance, ask how much the payout is to ensure you don't take too much cover. Check your contract or ask the human resources department. Energy bill: Actually knowing the units you use, and when, can help you slash your bills Don't just blindly pay your energy bill; question how many units you use, and at what times of day. Actually knowing the units you use, and when, and not just the final cost can help you slash your bills - and it may be that you have been overpaying and could be owed by your supplier. As a guide, the average household uses 3,300kWh of electricity and 16,500kWh of gas a year - which works out as roughly £1,300 a year. Some suppliers, such as British Gas and Scottish & Southern Energy, give out gadgets that show you how much energy you use at certain times of the day. You may be lucky enough to have a company pension - but do you know what type it is, and where it is invested? The Archbishop of Canterbury last week was embarrassed to discover that the church's pension had indirectly given money to payday lender Wonga - a company he had criticised. You need to know where your retirement savings are invested; not just to check it's not in companies you don't like, but also to ensure it's not just rotting away in dud funds. You want your savings to be working hard for you. In general, the younger you are the more risk you can take with your pension. Your payroll or human resources department will have details of your pension scheme, and its annual report should reveal more about its investments. Research your fund's performance, and how they fare against rivals, on sites such as trustnet.com or Morningstar.co.uk. How much money do you think you will need to live on when you retire? £20,000? £30,000? What will the state pension pay you? And what will your other pensions deliver? You have to get on top of these questions or face an impoverished retirement. The average pension fund built up by a saver over a working lifetime is still less than £30,000. That will give you just £125 a month. Add in the state pension and you'll get around £560 a month. To match the average UK salary of £26,500 a year, you'll currently need to build up a pension pot of more than £530,000. Your annual pension statement will tell you what your current savings will give you. Companies such as Hargreaves Lansdown and Virgin Money also have calculators to help you figure out how much more cash you need to save. It's a pretty dull question that appears on most home insurance forms: what type of locks do your doors and windows have? You probably don't give it a moment's thought. But your premiums could plummet if you know the precise type of bolts and catches. A five-lever mortice deadlock conforming to BS 3621 should be the minimum standard you need. The most secure tend to be a Rim automatic deadlatch with key-locking handle. If you get this information wrong, your insurer could quibble over any claim and even fail to pay out. When you die, any life insurance payout will be included as part of your estate - leaving your loved ones with a possible inheritance tax bill of 40 per cent if you have more than £325,000, or £650,000 for a couple. You can help avoid this by simply writing the policy "in trust." Most insurers will allow you to do this with old policies for free - you'll need to contact them directly and fill out a form. If you're taking a new policy, be sure to do it then. If you suddenly lost your job, you'd need a financial cushion of around six months" pay. So how long will your nest egg last? For most people, according to insurer Legal & General, it is just 18 days. So tot up how much you actually have in your bank account, Isas and savings accounts - but don't include pensions as you cannot legally get to this cash if you are under 55. Before you buy anything check what offers your employer has - many big companies have perks and vouchers, which could save you cash. For example, so-called "salary sacrifice" schemes allow you to buy things, such as bicycles, before income tax is deducted from your pay - so it costs you less and saves your company tax and National Insurance. See cyclescheme.co.uk. Some companies give you cash for untaken holiday. Bigger firms have Sharesave schemes; giving you stocks in your company on the cheap. And others have vouchers and offers for shopping. Ask human resources, check out the company noticeboard, and talk to your colleagues.