This article explains how Address Validation for Dynamics 365 handles postal codes (including the US ZIP+4 extended format) and how unit/suite numbers are preserved during validation.
Standard and extended postal codes
Many countries use a postal code that has both a short "base" value and a longer "extended" value – the most familiar example is the US ZIP+4 (for example, 10014-2617). To capture the extra precision without breaking systems that expect the short form, the product writes to two fields:
Postal Code (Zip) – the value most integrations expect.
Extended Postal Code (ExtendedZipCode) – the fullest, most precise value available.
Map one or both of these to columns on your record through your Field Mapping configuration. If you only need the short code, map the Postal Code field; if you want ZIP+4 precision, also map the Extended Postal Code field.
How postal codes are filled by country
The rules below are applied consistently across providers so results do not vary by API:
| Country group | Examples | Postal Code | Extended Postal Code |
|---|---|---|---|
| Base + extension | United States (ZIP+4), Brazil, Japan | Base code (e.g. 10014) | Full code with extension (e.g. 10014-2617) |
| Alphanumeric "X1X 1X1" | Canada, United Kingdom, Netherlands, Malta, Bermuda, Ireland | Full code | Full code (same value) |
| All other countries | — | Base code | Base code (same value) |
Because the Extended Postal Code always contains the fullest available value, you can safely map it everywhere and still get a sensible result in countries that do not use an extension.
Unit and suite number preservation
Some providers – notably Azure Maps – do not return the unit or suite number as part of the corrected address. In earlier behavior this could cause the unit/suite value to be dropped on write-back. The product now preserves the unit/suite number exactly as the user entered it when the provider does not return one, so apartment, suite, and unit details are never lost during validation.
Melissa Personator returns the suite as part of the standardized Address Line 1 (for example 9645 Gerwig Ln Ste 200), and the product writes that line as returned, including directionals. If you map a Unit Number field, the suite is written there and removed from Address Line 1. A suite typed in Address Line 2 is moved into Address Line 1 by Melissa, and Address Line 2 is cleared.