My experience of O2 has been a successful one for at least 5 years now. I have always been with them on their pay and go schemes, originally through receiving a free sim card (you often see these advertised on website banners etc or from the O2 website).

When I was younger, and stupid with money, my mum wouldn't let me have a phone on contract as I was spending about £100 a month on top ups (she never did understand that with contracts you get free minutes and texts! But she was probably right not to let me have one) Over the years O2 has gotten better, and from what I can remember, I have changed my number with them 2 or 3 times to get a better deal.

I used to be on a deal where if I topped up £10 per month I would get 300 free texts, and 500 for £15, you also get the whole £10/15 to spend on calls, and additional texts. This was working out fine for me, although most months I would run out of free texts, but I don't make many calls so this was fine, credit wise.

In al the years I have been with O2 I have never needed to have any contact with their customer service, until recently. I noticed a banner on a website in December that was offering unlimited text and web for £10 a month 'click here for your free sim'. I frantically 'googled' the deal and search O2's website to find out if there was a way to move to this deal and keep my number. I was unsuccessful in my search so decided to use the contact section of O2.co.uk to find out more.

A member of the customer service team emailed me back very quickly and explained that he could move my tariff over without having to change my number or even get a new sim card. He explained that this wouldn't take place until 3rd of January due to my top-up anniversary date (the minimum top up tariffs from O2 expect you to top up by the same date each month) I explained this was fine and then he processed it for me. I then got a text that I had to reply (for free) to, to confirm the changes.

On Jan 1st I got another text and email to remind me of the changes, and both communications offered me the chance to change my mind.

Over all I think I have a very good deal from O2 now, and the customer service team were very efficient. I know not many people use pay and go anymore, but I am a student who has no control over spending, so it works out great for me. The signal I receive on my phone is never an issue either.

Also you may have seen O2's advertisements for their surprises promotion, this is a text that you receive every time you top up. They send you a code to put into the promotion page on their website, to be in with the chance of winning prizes, the more you top up the better prizes you will be in with a chance for. I only ever get £10 top up so usually end up with things like free minutes to use at certain times etc.

if you are not currently a pay and go customer and are worried about the hassle of topping up then don't-it is simple. I usually do it over the phone with my debit card, and after you have used the same card a few times, it will only require you to punch in the last 4 digits of you card number, so it is very quick and the call is free. You can also top up on their website, buy getting a voucher over the counter in supermarkets and many other shops, and at most atm cash machines.

I would recommend parents looking into this great deal for their children, or anyone else who needs an emergency phone number for cheap!