Editing 999 (emergency telephone number) (section)

===Location===
The caller's location will not be passed onto the emergency services immediately, but it is possible to trace both landline and mobile telephone numbers with the BT operator; the former can be traced to an address. The latter can be immediately traced to a [[grid reference]] according to the [[transmitter]] being used.<ref>{{cite web |title=Enhanced 999 facility for mobile phones |url=http://media.ofcom.org.uk/2004/01/15/enhanced-999-facility-for-mobile-phones/ |date=15 January 2004 |website=Ofcom |access-date=7 June 2012 |archive-url=https://web.archive.org/web/20130606191708/http://media.ofcom.org.uk/2004/01/15/enhanced-999-facility-for-mobile-phones/|archive-date=6 June 2013 |url-status=dead }}</ref> However, this is only accurate to a certain wide area – for more specific traces, authority must be sought and an expensive operation can be conducted to trace the mobile phone to within a few metres. A number of smartphone apps can now be downloaded that assist with caller location by using the smartphone's satellite navigation features.

Since 2014, smartphones which implement [[Advanced Mobile Location]] will detect that an emergency call is being placed, and use any available location services (WiFi or GPS based location) to send an emergency SMS containing an identifier for the call and the phone's location, accurate to 30 metres.<ref>{{Cite web|url=https://www.computerweekly.com/news/2240234212/Advanced-Mobile-Location-pinpoints-999-calls-to-inside-30m|title=Advanced Mobile Location pinpoints 999 calls to within 30m|website=ComputerWeekly.com|language=en|access-date=4 May 2019|archive-date=22 March 2019|archive-url=https://web.archive.org/web/20190322033108/https://www.computerweekly.com/news/2240234212/Advanced-Mobile-Location-pinpoints-999-calls-to-inside-30m|url-status=live}}</ref> This is intended to be received by the mobile operator whilst the call is in progress.<ref>{{cite web |title=Location information for emergency calls from mobile phones |url=http://stakeholders.ofcom.org.uk/binaries/consultations/emergency-mobiles-cfi/statement/Emergency_Mobile_Location_Information_Statement.pdf |website=Ofcom |access-date=2 January 2016 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304095801/http://stakeholders.ofcom.org.uk/binaries/consultations/emergency-mobiles-cfi/statement/Emergency_Mobile_Location_Information_Statement.pdf |url-status=live }}</ref>

On some occasions callers will be put through to the wrong area service – this is called a "misrouted nines".<ref>{{Cite web|title=Delayed or inaccurate mobilising of resources - OPS {{!}} NFCC CPO|url=https://www.ukfrs.com/guidance/search/delayed-or-inaccurate-mobilising-resources|access-date=2021-09-20|website=www.ukfrs.com|archive-date=20 September 2021|archive-url=https://web.archive.org/web/20210920212411/https://www.ukfrs.com/guidance/search/delayed-or-inaccurate-mobilising-resources|url-status=live}}</ref> The most common reason for this is when a mobile phone calls 999 and is using a radio transmitter that is located in another force area; most frequently these are calls that are made within a few miles of a border. Upon establishing the incident location, the emergency service operator will relay the information to the responsible force for their dispatch. In most areas, forces will respond to incidents just beyond their border if they could get there quicker, assist, and then hand over to other forces when they arrive.

On strategic routes like almost all motorways and some major A roads in the United Kingdom, [[National Highways]] have placed blue [[driver location signs]] with the location printed on them, at approximately 500-metre intervals. Although emergency [[Emergency telephone|SOS phones]] are placed along the [[Shoulder (road)|hard shoulder]] on all motorways (and in emergency refuge areas on [[smart motorway]]s) which automatically send location information to the National Highways regional control centre (RCC), most people involved in a road emergency call from their mobile phones and so need another way to identify their location. These signs contain a code which can be given to the emergency operator or the RCC. For example, a sign may say "M1 A 100.5". This translates as the M1 motorway, on the "A" carriageway, at 100.5 kilometres from the M1's nominal start at [[Staples Corner]].<ref name=":0">{{Cite web |url=https://www.theaa.com/breakdown-cover/advice/driver-location-signs |title=Driver location signs |website=[[The Automobile Association]] |access-date=25 July 2018 |archive-date=25 July 2018 |archive-url=https://web.archive.org/web/20180725214555/https://www.theaa.com/breakdown-cover/advice/driver-location-signs |url-status=live }}</ref> The "A" and "B" carriageways are designated by Highways England to each carriageway, dependent upon which direction it travels; these normally refer to whether the carriageway goes "Away from London" or "Back to London". On circular motorways like the [[M25 motorway|London Orbital M25]] and [[M60 motorway|M60 Manchester Outer Ring Road]], the clockwise carriageway is the A carriageway and the anti-clockwise carriageway is the B carriageway. Letters J, K, L and M refer to slip roads at junctions. These signs are in addition to the pre-existing 100m distance marker posts alongside the carriageway.<ref name=":0" />