# Address register

An address register is a country's official file of every address its authorities recognise, usually keyed on buildings rather than letterboxes.

Date: 2026-09-10

An address register is a country's official file of the addresses its authorities recognise, usually keyed on buildings rather than letterboxes. Six are installed here, and each publisher states how complete its own file is.

## What Spaw answers

`exists` is the answer, and the rule behind it is the strictest thing in the address product. It is true only on a `premise` match — the building itself was found. It is false only when the register that answered claims to list every address in its country and does not carry this one. In every other case it is null.

`match_level` says how far the address could be followed: `premise`, `street`, `postcode` or `none`. `register` names the file that answered and `register_coverage` reports `complete` or `partial`. Always read `exists` against that last field.

## Why null is the common answer

Two of the six registers are partial by their publishers' own account: the American national database is contributed to voluntarily by states and local authorities, and the French one is still filling in. An address missing from a partial register may simply be in a part nobody has shared yet, so absence there is not evidence and the field says null instead of false.

The `not_in_register` risk signal (+20) fires only where `exists` is false — that is, only where a complete register was asked and answered.

Reference: https://spaw.co/glossary/address-register