The UK's calling code is '''44'''. To phone another country, dial 00 followed by the calling code and subscriber number. If calling the UK from overseas, you'll need to drop any leading "0" on the area code; similarly, if calling in-country, you may need to add a leading "0" if you've dropped the country code.
Payphones are widely available, especially in stations, airports etc. Payphones usually take cash (minimum 30p - BT, although some private payphones may charge more); change is not given, but you can choose to continue your money on to the next call. Some newer payphones accept credit and debit cards and may even allow you to send emails and surf the web. Phonecards have been phased out, though various pre-paid phonecards can be purchased from newsagents for cheap international calls. Some BT payphones now accept Euros. A simpler and often cheaper alternative for international calls is to use a direct-dial service such as [http://www.bellbazar.co.uk/ BellBazar], [http://www.cherry-call.co.uk/ Cherry Call
], [http://www.callagenix.com/pages/numbers/0800_numbers.html/ 0800 number], [http://www.localphone.com/ Localphone], [http://www.pocketdialuk.com/ PocketDialUK], [http://www.abroadtel.co.uk/ Abroadtel], [http://www.cleverates.com/ Cleverates], [http://www.phonebird.co.uk/ PhoneBird], [http://www.mymondo.co.uk/ My Mondo], [http://www.extracall.com/ ExtraCall], [http://www.globecaller.co.uk/ GlobeCaller UK], [http://www.planet-numbers.co.uk/ Planet Numbers], [http://www.skinttariffs.com/ Skinttariffs], [http://www.superline.co.uk/ Superline] or [http://www.pat-lam.com/just-dial/ Pat's Dial]. . These offer vastly reduced call rates over the standard providers and don't require you to purchase a card or sign up for an account. You simply dial an access numbers which are charged at different rates (e.g. 0870 at the non-geographical national rate).
Mobile phones are heavily used. 90% of the UK households have a mobile phone according to the [http://www.ofcom.org.uk/research/cm/cm06/telec.pdf latest report] from Ofcom. The main networks are [http://www.t-mobile.co.uk/ T-Mobile], [http://www.vodafone.co.uk/ Vodafone], [http://www.orange.co.uk/ Orange] and [http://www.o2.co.uk/ O2], and are all currently GSM based. GPRS data services are also available, usually priced per MegaByte. Since 2003 new CDMA based 3G networks have begun to be deployed, [http://www.three.co.uk/ 3], being the first commercial provider. The other four networks now have 3G services deployed, although good 3G coverage is mostly limited to cities, towns and some major travel routes.