Postal Code Finder
Registry / United Kingdom / Postal code prefixes / CM2 / CM21 /

Postal code CM21 in Allen's Green, United Kingdom

Postal code CM21 is mapped to 3 locality records in United Kingdom with administrative hierarchy and coordinates.

Verified data profile for Postal code CM21

Based on 3 records, 1 postal code values and 3 mapped localities. Coordinate coverage is 100.0%.

3
Records
1
Postal identifiers
100.0%
Geocoded
CM21
Example code
Postal code Locality Administrative path Coordinates
CM21 Allen's Green England / Hertfordshire 51.8167, 0.15
CM21 High Wych England / Hertfordshire 51.816, 0.1188
CM21 Sawbridgeworth England / Hertfordshire 51.8167, 0.15

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Postal code range

This code belongs to the CM2 prefix range for United Kingdom.

View all CM2 postal codes

How to validate postal code CM21

Treat CM21 as a text value, not a number. Postal identifiers can contain leading zeroes, spaces or letters in other countries, so applications should validate the country and original string together. For this page, the code is valid when it appears with one of the mapped localities below and the administrative path belongs to United Kingdom.

United Kingdom lookup
Open the country-level hierarchy and dataset exports.
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Compare this code with neighboring country ranges.
Prefix CM2
View related codes in the same prefix range.

Mapped localities

Allen's Green
England / Hertfordshire
51.8167, 0.15
High Wych
England / Hertfordshire
51.816, 0.1188
Sawbridgeworth
England / Hertfordshire
51.8167, 0.15

Common lookup mistakes

A postal code can map to more than one locality record, and the same locality name can appear in different administrative areas. Always compare the country, postal code, place name and region together before treating a match as final.

Coordinates on this page are useful for map previews and approximate area checks. They should be read as locality or postal-area centroids, not as exact delivery addresses. For bulk validation, download the country dataset and keep this canonical URL as the human-readable reference for the code.

Nearby postal code lookups

These neighboring identifiers help compare adjacent code ranges inside United Kingdom. Each link opens a canonical postal-code page with its mapped places and administrative context.

CM18
Harlow
CM19
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CM2
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CM20
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CM22
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CM23
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CM24
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CM3
Althorne