Changing SIM Card?

I am thinking about purchasing an unlocked GSM mobile phone in the US before I come to London.  I have seen that I can get a better phone for the money.  My question is how easy is it to pop in a SIM Card (on prepay) and start talking?

Thanks

Yo Joshua!
Good news is that's its easy peasy to pop in a Pay as you go SIM and start yappin right away! - Be careful of course wanting to call back to the US on that SIM card, it'll probably be really expensive! Ensure that you get yourself a Tri -Band handset as well. Check Carphone warehouse.co.uk website for the lowdown on pay as you go SIM cards and their rates etc and you should be all good to go once you touch down in the UK!

HTH!

Dennis! West London UK!!

Changing the SIM card is simple.  You just remove the back of the phone, slide out the old one, and insert the new one.  On some phones you have to remove the battery to gain access to the SIM slot, but it's still only a 2-minute job from start to finish.

Be careful with the tri-band issue, as "tri" can mean different things to different manufacturers.   For best overall coverage in the U.K. you need both 900 and 1800MHz bands.   

What about going the other way...from UK to US? 

What about going the other way...from UK to US? 

The original GSM band in North America is 1900MHz, so you will definitely need that.  The 850 band is also being used more as GSM service expands across the U.S., especially in more rural areas. 

The fact that four different bands are used (two American, two European) is why it's important to realize that a tri-band phone can mean different things:

900/1800/1900  will give full European coverage but more limited American coverage
850/900/1900 will give full American coverage but restricted European coverage

Quad-band phones are likely to become more common in order to cover all bases.
 
Have a look in the Technical Issues thread, starting at reply #10, for some more detailed background information.

I've had no problems taking my Motorola V3 and XDA2i units to the US and plugging in a T mobile pay as you go SIM to make calls within the USA. I had to tell T mobile USA the IMEI number of my handsets so that they 'knew' my handsets would be on their network - but that was no problem at all.

Coverage on T mobile outside of city areas isn't so good - and on interstate roads non existent once your out of built up areas - which is something UK mobile phone users are not used to! you've now got to go real far off the beaten track to not have any signal in the UK - in the USA it seems mainly only in built up areas only - not much use if you breakdown I guess!

HTH

Dennis! West London UK!

There are several factors at work.   Britain has  50+ million people packed into a country which is about the same size as Oregon.   Providing service across the much vaster rural areas of America is clearly on a totally different scale and presents quite a challenge.

The other thing to remember is that GSM is still very much the Johnny-come-lately of cellphone technologies in the U.S.A.    There are still some states which have no GSM service at all, instead having just the older American CDMA, AMPS systems, etc.

In fact the closure of old analog cellular networks is giving cause for concern in more thinly populated regions:

Residents Fight to Keep Analog Cell Phones

I have a suggestions that may help -

As yourself, my Vodafone roaming bill while in the states was huge, every month at least 500.00 GBP !!!! So I purchased a $99.00 tri-band Nokia T-Mobile pre-paid phone and now use it while I'm in the states, and save so much money.

Suggestion is: Get it unlocked in the UK. I was shopping and found this booth advertising the ability to unlock phones for ten pounds. Did it and it works great!
Now I can use my T-Mobile pre-paid phone with my Vodafone chip as a spare when I'm not in the states.

Hope this helps.