All area codes, including mobile numbers, start with a "0" (trunk prefix) for domestic calls.
Some telephone numbers deviate from this rule: All area codes including mobile start with a "0" (trunk prefix) for domestic calls.
The middle three-digit part is extended to four digits in many areas due to the increased number of telephone users.
Then follows 2 digits indicating to which Mobile Operator's pool the number originally belonged when it was taken into usage.
The fourth digit represents a "sub-group" of this pool and has no additional meaning other than increasing the amount of possible numbers.
Danish short numbers used for text messaging services have four digits and are written AAAA.
According to international convention, numbers are sometimes written +30 AAB BBBBBBB or +30 AAAB BBBBBB to include the country calling code.
Phone numbers in Iceland have seven digits and generally written in the form XXX XXXX or XXX-XXXX.
The use of hyphens is discouraged, particularly on websites as it can prevent mobile browsers identifying the number as a clickable link for easier dialling.
The Irish telecommunication regulator, ComReg has been gradually rationalising area codes by merging and extending local numbering to 7-digits in the format 0AA BBB BBBB.
This means that varying fixed line number lengths will continue to exist in Ireland for the foreseeable future.
Alphanumeric characters can also be used in presenting numbers for added memorability, but it is much less common than in North America.
Since 10 October 1995 (Operation Decibel) all telephone numbers in the Netherlands have ten digits (including the trunk prefix '0').
The groups of digits in the local subscriber's number (B) are separated by dashes ('-'): BBB-BB-BB, BB-BB-BB, B-BB-BB.
The area code is included in parentheses, similarly to E.123 local notation: (AAA) BBB-BB-BB, (AAAA) BB-BB-BB, (AAAAA) B-BB-BB.
Spanish telephone numbers have nine digits, starting with '9' or '8' for fixed lines (excluding '90x' and '80x') or with '6' or '7' for mobile phones.
The numbers are written with the area code followed by a hyphen, and then two to three groups of digits separated by spaces.
Calls to numbers which were carried to another operator are signaled by a unique sound upon dialing, to signify that the recipient is on another network and alert them against potentially unwanted interconnection charges.
Due to the need for a larger telephone number pool in many regions, seven-digit dialing is becoming rare in the United States.
In general, placing long-distance calls requires dialing the trunk code 1, but this may be optional in some areas.
The Canadian government has stated on its Language Portal of Canada that telephone numbers are to be written with a hyphen between each sequence, as follows: 1-NPA-NXX-XXXX or NPA-NXX-XXXX.
[16] 10-digit dialing is now required throughout most of Canada, including all of British Columbia, Alberta, Saskatchewan, Manitoba, Quebec, Nova Scotia, Prince Edward Island, Newfoundland and Labrador, and Ontario.
In the province of Québec, where French is the first language, the Office québécois de la langue française has established that telephone numbers must be written with spaces first and then a hyphen for the last sequence, as follows: 1 NPA NXX-XXXX.
As of August 3, 2019 all the indicators and access codes (01, 044, 045) are deprecated, therefore all telephone numbers, for landline or mobile service, are dialed with ten digits.
[21] The formatting convention of a telephone number is The international country code prefix for Mexico is 52.
Sometimes, a prefix is reserved for official numbers, that is for offices depending on the national, provincial or local state.
Mobile phones use the same area codes as landline telephones, but the number begins with a "15", added to a string of 6, 7 or 8 digits, just as described above.
To sum up, given the mobile phone (011) 154-123-4567, you will call it by dialing: And you will send messages to: Two sorts of special numbers exist in Argentina.
On the one hand, three-digit numbers are used for special services such as to call the police, fire brigade or emergency doctors, as well as to hear the official time.
These include (but are not limited to): (where the xxx indicates the same digit dialled three times, and a, b, c and d may each be any of the ten digits) 0800 lines are used by companies, and it is the receiver and not the caller who pays for the call, so that potential clients are encouraged to contact business companies for free.