Many consumers have experienced this unfortunate monthly shock, and for most of them it's their own fault. It's sad but true that a great many mobile customers are too lazy when it comes to their phone costs and are wilfully ignorant of their phone contract's terms and conditions and their inclusive call and text limit.

Here we take a look at some easy ways for you to cut some of these hefty mobile costs.

Top tip 1? check your existing mobile package. Make sure you know how many inclusive free texts and call minutes you are entitled to. If you often find yourself running over your monthly allowance you should ask your provider to transfer you to a different tariff that suits you better. You may find that the line rental is higher per month, but you'll receive an increased number of free texts/minutes per month and so you'll be far less likely to be charged for going over your allowance.

Top tip 2 - look out for free text and call deals. Various advertisers have teamed up online to give free texts and call time to sixteen to twenty-four year olds. In exchange, they must agree to receive up to 6 multimedia messages each day from advertisers. So if you can put up with daily adverts you could save yourself some cash.

Top tip 3 ? avoid the upgrade! Your provider could be tempting you with the latest flashy mobile phone handset at the start of your new contract, but beware as the cost of this new toy will be priced into the cost of your new contract. There's no such thing as a free lunch, as they say, and there's no such thing as a free iPhone unfortunately. Instead you may be better buying the handset yourself and opting for a cheaper SIM-only contract. You'll still get free calls and texts, but you'll never be tied to a contract for more than thirty days, so you can easily switch if it isn't working out.

Top tip 4 - SIM-sharing. Many network providers such as o2, Vodafone and Virgin Mobile now offer you several SIMs together in one cheap package ? if you share these out between friends and family you'll have limitless free call time and text messages to one another.

Top tip 5 - put your old phone to good use. You can trade in your old phone towards the cost of a new one? Most mobile phone shops offer this service and it can get you more than ?20 off the cost of your new phone.