UK Postcode & Location Search Explained
Location is one of the most powerful ways to segment UK companies.
On firmlist, postcode and location filters allow you to focus on where companies are registered, helping you build geographically relevant lists for sales, research, logistics, or compliance.
This guide explains:
- how UK postcodes work
- what postcode prefixes mean
- why location matters for B2B searches
- how to use geography intelligently (not naively)
Why location matters in company searches
Geography affects:
- buying behaviour
- regulation and incentives
- logistics and serviceability
- regional industry clusters
Examples:
- A local accountant may only serve companies within 20-30 miles
- A regional supplier may target specific cities or counties
- Analysts may want to understand where industries concentrate
Location filtering lets you reduce noise and increase relevance.
What location data does firmlist use?
firmlist uses the registered office address recorded at Companies House.
Important distinctions:
- This is the legal address, not always the trading location
- Some companies use accountants, agents, or virtual offices
- Despite limitations, registered address remains the most consistent public location signal
For large-scale analysis, it is still extremely useful.
How UK postcodes are structured
UK postcodes are hierarchical and highly granular.
Example:
SW1A 1AA- SW — postcode area
- SW1 — postcode district
- SW1A — postcode sector
- SW1A 1AA — full unit postcode
firmlist typically allows searching by postcode prefix (area or district), which balances precision and scale.
Postcode prefix searching (how to think about it)
Postcode Area (e.g. M, B, LS)
- Covers a large geographic area
- Useful for regional or city-wide targeting
- Good for high-level market sizing
Example use cases
- "All companies registered in Manchester (M)"
- "All Birmingham-based firms (B)"
Postcode District (e.g. M1, B15, LS1)
- More precise than area
- Ideal for local services and outreach
- Reduces dilution from wide regions
Example use cases
- Local trades and services
- City-centre focused businesses
- Hyperlocal research
Why postcode density matters
Some postcode areas contain far more companies than others.
Factors influencing density:
- Population size
- Commercial centres
- Availability of registered offices
- Presence of accountants and company formation agents
Examples (illustrative):
- London postcode areas contain very high company density
- Rural postcode areas contain far fewer registered companies
Understanding density helps you:
- interpret search result volumes correctly
- avoid assuming demand where none exists
Using location filters for B2B strategy
Local sales and services
If you offer services that depend on proximity:
- accounting
- legal
- facilities management
- in-person consulting
Use district-level postcode filtering.
Regional or national campaigns
If delivery or service is remote:
- software
- online services
- national suppliers
Use area-level postcode filtering combined with industry (SIC) and company size.
Market research and analysis
Location filters are invaluable for:
- mapping industry clusters
- comparing regional activity
- identifying underserved regions
Combining postcode with other filters (best practice)
Postcode filtering is most powerful when combined with:
- SIC codes (industry)
- Company type (LTD, LLP, etc.)
- Company status (active only)
- Company age (new vs established)
Example:
Active LTD companies, SIC 62012 (business software), incorporated in the last 5 years, postcode areas SW and EC.
Common mistakes to avoid
Assuming registered address = trading location
Always remember:
- registered office ≠ operational site
- especially true for micro-companies and holding structures
Over-filtering geographically
Combining very tight postcode filters with niche SIC codes can produce very small datasets. Adjust scope accordingly.
Browse by location
Explore companies by major UK business hub:
| City | Postcode Prefix |
|---|---|
| London | E, EC, N, NW, SE, SW, W, WC |
| Manchester | M |
| Birmingham | B |
| Leeds | LS |
| Glasgow | G |
| Bristol | BS |
| Edinburgh | EH |
| Liverpool | L |
| Cardiff | CF |
| Belfast | BT |
Related guides
- Company Types Explained
- Company Status Explained
- SIC Codes Explained
- Company Numbers & prefixes
- Company age & incorporation date
- Other indicators