Area Code 11 – Colombo

Geographic Overview

The +94 11 area code is the National Destination Code (NDC) for Colombo, the commercial capital and largest city of Sri Lanka. Administered under the Sri Lanka Telecommunications Regulatory Commission (TRCSL), this code covers the Colombo District and its immediate suburbs, including Fort, Pettah, Cinnamon Gardens, Bambalapitiya, Wellawatte, Dehiwala-Mount Lavinia, and Moratuwa. As a geographic code, it routes calls to fixed-line (PSTN) services within the Colombo metropolitan area.

Dialing Formats

For local callers within Sri Lanka, the trunk prefix '0' is used before the area code, followed by the subscriber number. The complete national format is 0 11 XXXX XXX (where X represents the 7-digit local number). For example, a Colombo landline number might be dialed as 011 234 5678 from anywhere in the country.

International callers must replace the trunk prefix with Sri Lanka's country code +94, omitting the leading '0'. The international format becomes +94 11 XXXX XXX. For instance, calling the same number from abroad would be dialed as +94 11 234 5678.

Number Structure and Overlays

Colombo numbers are 8 digits long in national format (including the leading '0' and the 7-digit subscriber number). The area code '11' is a closed numbering plan component, meaning the subscriber number length is fixed. There are no overlay codes currently in effect for Colombo; the '11' code remains exclusively assigned to the geographic region. However, with the growth of VoIP and fixed wireless services, some numbers under this code may be allocated to operators using alternative technologies, but they remain geographically associated with Colombo for routing purposes.

Calling Instructions

• Local callers (within Sri Lanka): Dial 011 followed by the 7-digit subscriber number. Example: 011 234 5678.
• International callers: Dial your country's exit code (e.g., 00, 011), then 94, then 11, and the 7-digit subscriber number. Example: 00 94 11 234 5678 from most European countries, or 011 94 11 234 5678 from the US/Canada.

When dialing from a mobile phone, the same international format applies. It is important to note that omitting the leading '0' when dialing internationally is mandatory; including it will result in a routing error.

Regulatory and Technical Notes

The +94 11 code is part of the E.164 numbering plan and is managed by the TRCSL. Number portability is not yet fully implemented for fixed-line services in Sri Lanka, so numbers under this code are generally tied to the physical location of the exchange. For businesses, having a Colombo landline number can enhance local presence and trust, as many organizations and government offices are based in the capital. When contacting services such as banks, utilities, or embassies in Colombo, expect to encounter this prefix.