Telephone numbers in Singapore, also known as the National Numbering Plan, are regulated by the Info-communications Media Development Authority. Due to the small geographical size of Singapore, there are no area or trunk codes; all numbers belong to one numbering area, and thus come in the same 8-digit format. Numbers are categorised based on the first digit, thus providing ten possible categories, of which six are currently in use and the remaining four reserved for future usage.
History
Until 1985, subscribers' telephone numbers in Singapore were five and six digits. Five digits were introduced in 1960s, whereas 5-digit and 6-digit phone numbers were introduced in 1960s as fixed lines grew, but in that year, these changed to seven digits as the introduction of new towns arose and a large number of new numbers were required. Rationalisation was based on geographical locale over the 12 years. On 1 September 1995, the digit '9' was added to the front of mobiland pager numbers, making numbers eight digits, and on 1 March 2002, the digit '6' was added to the front of existing fixed line telephone numbers. The migration to the 8-digit numbering plan was planned to be on 2002, ahead of 2004 deadline. Full telecommunication liberalisation in April 2000 led to rapid growth in the market, resulting in increased demand in numbers. The implementation of 8-digit numbering plan, ensured that there would be a sufficient number resource pool to cater to the expanded telecommunication services. Preparation work started in 1999, as an effective approach had to be worked out for the implementation, with minimum service disruption and inconvenience to customers. The public telecommunication service providers - SingTel and StarHub, implemented the 8-digit numbering plan and ensure smooth service continuity for their customers after the migration. There was a parallel run of 7-digit and 8-digit numbers from 1 March 2002 to 31 March 2002. From 1 April 2002 to 30 June 2002, those calling the 7-digit numbers would hear the number change announced, prompting them to add the digit "6" to the old number, after which the call would be disconnected. After 30 June, callers would hear the announcement that the number was unavailable. In March 2004, in response to the growing mobile phone numbering in Singapore, 8-digit mobile phone numbers starting with the digit "8" were introduced.
Until 1995, calls to Malaysia from Singapore were direct and similar to domestic phone calls, with only the area code for fixed line or Malaysian mobile phone code and number being required, hence 03 for Kuala Lumpur fixed line or 019 for Celcom mobile carrier were dialed instead of +60 3 and +60 19. In 1995, owing to the divergence of the two countries' numbering plans, the Subscriber Trunk Dialling prefix 020 was adopted. For example, in order to call a number in Kuala Lumpur, 020 is dialled first, followed by the area code 3, then the subscriber number. Similarly, calls to Batam, Samarinda, Pekanbaru and Tanjung Pinang in Indonesia require only the code 011, followed by the area code and the subscriber's number, hence to call a number in Batam from Singapore, a subscriber would dial 011 778 xxx xxx, instead of the international code +62 778. Calls to the rest of Indonesia, including those to mobile phones, require international dialling. Following the liberalization of the telecommunications industry, new carriers are assigned new carrier-specific codes for international and regional trunk call services. The codes 020 and 011 are assigned to the incumbent carrier SingTel. The other two major carriers, M1 and StarHub, do not offer any special dialling arrangements for calling to Malaysia and Indonesia, instead requiring full international dialling, the same as calling other countries.
3xxx xxxx - Business and Corporate IP Telephony Services 6xxx xxxx - Public Switched Telephone Network and Residential IP Telephony Services 8zxx xxxx - Mobile, Data Services, New Numbers and Prepaid Numbers 9yxx xxxx - Mobile, Data Services and Pager
This is the list of telephone exchanges in Singapore. They also share the telephone exchanges with OpenNet locations, cable TV and '6'-regoed phone lines.
The generic international call prefix when making an international call is 000, which all telecommunications service providers are required to share. However, the code is not well known as carrier-specific access codes are generally used, such as 001 for SingTel, 002 for M1 and 008 for StarHub. On a mobile phone, a plus sign can be keyed in as a substitute for the prefix. VoIP services, such as Zone 1511, use prefixes in the 15xx range. For example, to call a number in London using Zone 1511, a subscriber would dial 1511 44 20 xxxx xxxx. hhAccess codes in the 0xx range indicate a Tier 1 VoIP provider. Access codes like 1xxx are indicative of a Tier 2 VoIP provider.