A local name for a postal system
ZIP Code is the term used by the United States Postal Service. Postal code is a general term used across countries. A form asking for ZIP or postal code usually expects the code for the destination, not necessarily a US ZIP Code.
Keep the code as text
Some codes contain letters, spaces or leading zeros. Store and copy them as text so that software does not drop a zero or interpret a code as a number. An allowed pattern is only a format check; it does not prove that a code exists.
Use the country to disambiguate
The same digits can occur in multiple countries. Choose the destination country when searching. If several localities share a code, compare their administrative regions and use the recipient’s complete address rather than guessing.