The majority of people with mobiles are signing up to big contracts they don't need, according to new research.
It's because people are worried about being hit in the pocket if they go over their minutes, so they end up overpaying by around £200 a year.
Billmonitor analysed more than 28,000 bills of all the main network providers, except 3.
They say three-quarters of mobile subscribers pay for more minutes than they need because of fears over big and unpredictable bills.
Newsbeat caught up with some listeners to find out their views on mobile phone bills.
Rosie Griffin, 20
I never use all of my minutes and I'd die without unlimited texts. I pay £35 a month - it is worth it but I'd like to pay a little bit less. I am on my phone 24/7, I never put it down, I'm on it constantly until I go to sleep.
I get 600 minutes a month. I think I use about 400. I text a lot more. I wish I could pay a bit less! I Only ever go over if I send some picture messages.
I had a Blackberry before so data was fine but I don't have an idea how much I'm using. I just go on Facebook or internet shopping but I have no idea how much data costs - I don't even know how much I'm allowed!
I think phone companies should deduct money at the end if you don't use all your minutes - but it's alright.
Alec McSimpson, 29
I have a contract for about 600 minutes, I normally use those each month because I use my phone for work. I might go just over but I'm pretty happy with it.
Contracts are complicated. I think if there was a system in place for people who were confused by it, that would be good.
I think when you get locked in for 18 or 24 months it does limit you. I understand the price of the phone is expensive but if you could upgrade before that would be brilliant.
Shauna O'Neill, 21
My contract is £35 a month. I get 1200 minutes - there's no way I ever use any of them. I get unlimited texts and I always have to pay for the internet. I only use Facebook on my lunch and I have to pay so much money!
I think I pay around £50 a month. It's too much money. I think I probably use about 200 minutes a month, but I'm not allowed to change my tariff. Apparently there are special rules for moving 18 month contracts.
I think after a few months you shouldn't be allowed to waste that much money, I was on pay as you go before and I was topping up a lot so that's why I took a big contract, but I don't use my phone as much any more!
Eve Malek, 19
I'm always talking on my phone, so I'm always going over my bill. I'm paying £45 a month when my contract is £35. I go over £10 to £15 every month.
I probably say I spend about two hours on the phone a day. My phone's always in my hand I just use it loads.
I have 11 months left on my contract, but I think it's too expensive. I'm either going to find a cheaper one or go on pay as you go so I'm more restricted, that way I will keep track of what I'm spending.
