Sri Lanka Postal Code Finder

Sri Lanka uses a 5-digit postal code administered by Sri Lanka Post (the Sri Lanka Postal Department). The format is fixed: exactly five digits, no letters, no spaces. The structure encodes geographic routing information in two parts.

First two digits — postal region. The leading pair identifies a district or postal region group. Codes starting with 00 belong to Colombo city subzones (Colombo 01 through Colombo 15, codes 00100 to 01500). Codes starting with 10 cover greater Colombo and the Western Province suburbs that ring the city — Sri Jayawardenepura Kotte, Nugegoda, Maharagama, Moratuwa, Panadura. The remaining ranges map onto districts: 20 = Kandy, 40 = Jaffna, 60 = Kurunegala, 80 = Galle, 90 = Badulla, and so on.

Last three digits — sub-post-office sequence. Within each region the trailing three digits identify a specific sub-post-office in allocation order. So 00100 is Colombo GPO (the parent post office in Colombo Fort), 00300 is Colombo 03 (Kollupitiya), and 00700 is Colombo 07 (Cinnamon Gardens). Sequence allocation is not alphabetic and not contiguous — gaps reflect historical openings and closures.

How the search works.The directory is bundled as a static JSON dataset inside the page — no network calls, no rate limits, no tracking. When you type a query the tool runs three passes against every record's name and alias list:

1. Exact match and starts-with match get the highest rank.
2. Word-boundary containsmatch comes next (so “galle” matches “Galle Fort”).
3. Fuzzy match via Levenshtein edit distance ≤ 2 catches typos like “negomba” → Negombo.

If your query is all digits the search switches to reverse-lookup mode: an exact 5-digit input returns the matching record, while a 1–4 digit prefix returns every code in that region. Optional district and province filters narrow the result set further.

Self-verification. The data module exposes a regionFromCodePrefix()cross-check that maps a code's first two digits to its expected province per Sri Lanka Post's documented system. Every record in the directory satisfies this invariant, and if a future update introduces a record whose declared province disagrees with its code prefix the UI shows an inline cross-check warning.

Why post offices, not addresses. Sri Lanka Post allocates one code per post office, not per street or building. A code like 10250 covers Nugegoda and every lane that posts through the Nugegoda office, so two houses a kilometre apart can share a code while a third house on the boundary routes through Maharagama (10280) instead. That is why the search keys on post office and town names rather than asking for a house number — you find the office that serves your address, then use its code. Postal codes are routing identifiers only; they are not personal identifiers like the National Identity Card number, which encodes date of birth and gender and is decoded by our Sri Lanka NIC decoder.

Every two-digit prefix maps to a district per Sri Lanka Post's published code structure. This table is the canonical reference used by the cross-check function in the data module.

Sri Lanka Post places the postal code on its own line, at the end of the address block, directly under the town. The standard four-to-five line domestic format reads: recipient name; house number and street; village or suburb; town; then the 5-digit code on the final line. For example, a parcel to Nugegoda is addressed with NUGEGODA on one line and 10250 on the line below it — never inline with the town and never prefixed with letters. Writing the code on a line of its own helps automated sorting machines read it cleanly.

On international forms the same 5-digit number goes in whichever field is labelled ZIP, PIN, postcode, or postal code; the country is always written as SRI LANKA in capitals on the last line. If a form rejects the code for being “too short”, the form is usually expecting a US 5-digit ZIP or a 6-digit format — the Sri Lankan 5-digit code is correct as-is and can be entered without padding. E-commerce checkouts that validate against a country list will accept it once Sri Lanka is selected as the country.

Postal codes also matter for delivery timing. Mail and parcels route through the parent post office named against the code, so an item to a rural code may add a day for onward delivery to the village. If you are planning around delivery windows — say, posting documents before a deadline — pair this finder with the Sri Lanka working days calculator to count past weekends and public holidays when Sri Lanka Post counters are closed. And when the address is a block of land described by deed rather than a street — common for plots in the outer districts — our land area converter turns perches, roods, and acres into the units a courier or surveyor expects.

• Sri Lanka Post — Official Postal Code Directory
• Sri Lanka Post (Sri Lanka Postal Department) — main site
• Universal Postal Union — Addressing Solutions (LK format reference)

Directory data was last reconciled against Sri Lanka Post on 2026-05-12. 70 post offices are currently bundled, covering all 25 districts and all 9 provinces.