omitted. For example, a call from the number (02) 5551 5678, to the number (02) 7010 1111, will be connected if the caller dials only 7010 1111. Similarly, a person who dials 7010 5678 on a land-line or mobile phone in Melbourne (i.e., within the 03 area) will be connected to 03 7010 5678. For this reason, landline numbers are often specified without the area code. If a person's number and the destination number share the same area code, then the area code is not required, even if it is not a local (untimed) call. However, the full international number must always be dialled, since the Australian telephone network has the capability to recognise when the destination required is either international, in a different national area or within the local area and to switch and charge the call accordingly. Thus, it is strongly recommended that telephone numbers should be stored in mobile phones in the form of the full international number, should the owner of the phone be likely to use the phone concerned in an area away from home, either within Australia or internationally. Mobile phones Within Australia, mobile phone numbers begin with 04 or 05 – the Australian national trunk code 0, plus the mobile indicator 4 or 5 – followed by eight digits. This is generally written as 04XX XXX XXX within Australia, or as +61 4XX XXX XXX for an international audience. Whilst this format may be viewed as incorrect, it is the result of mobile carriers advertising numbers in such a way so as to clearly identify the owning telco prior to mobile number portability, introduced on 25 September 2001. Prior to MNP, mobile operators generally reserved number ranges in blocks of 04 xy z. The xy-digit codes (sometimes xy z) are allocated per network, although with the introduction of number portability, there is no longer a fixed relationship between the mobile phone number and the network it uses. In 2015 the 05 prefix (other than 0550) was also reserved for digital mobile phones as a part of the Telecommunications Numbering Plan 2015. However, as of 2019 no numbers have been allocated with this prefix. Within Australia, mobile numbers must always be dialed with all 10 digits, regardless of the caller's location. Geographic numbers Geographical areas are identified by the first few digits of the local number: Central-East region (02) 02 37 Armidale, Tamworth, Northern