Accurate Northern Ireland Postal Codes Directory
Sending mail across the Irish Sea requires the exact alphanumeric routing format to prevent delays. Unlike other regions in the UK that use various alphabetical prefixes, all Northern Ireland Postal Codes start with the same universal identifier. Our 2026 database helps you navigate through different counties to find the exact sector and street-level dispatch code instantly.
Search Northern Ireland Postal Codes
Northern Ireland
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You can find all post codes of Northern Ireland in upper Search Tool.
List of All Regions Post Codes in Northern Ireland
The Structure of Northern Ireland Postal Codes
The addressing architecture in this region is unique and highly centralized.
The Universal Prefix (BT): Every single outward code in Northern Ireland begins with the letters ‘BT’, which stands for Belfast.
Routing Areas: Following the ‘BT’ prefix, a numerical identifier (from 1 to 94) indicates the specific geographical sorting district, covering everywhere from the busy streets of Belfast to rural areas in County Fermanagh.
Useful Guides for Northern Ireland Postal Codes
Need codes for other UK nations? Easily switch back to our main UK Postal Directory. If you are interested in the geopolitical history and geography of the six counties, check out this excellent Wikipedia overview of Northern Ireland.