Batch utility
Bulk Postal Code Validator
Paste rows or upload a CSV containing ISO2,postal code. The public tool handles up to 100 records and distinguishes documented format checks from active-snapshot matches.
How the validator interprets a row
A row has two independent checks. The format result uses a documented postal pattern only when a source-backed rule exists for that country. The snapshot result asks whether the normalized code appears in the active GeoNames import. A code may have a valid shape and still be absent from the current snapshot, or may be present even when no independently documented format rule has yet been curated.
Preparing a useful CSV
Use an ISO 3166-1 alpha-2 country code in the first column and preserve leading zeroes in the second column. Spreadsheet applications sometimes convert postal codes to numbers, which can remove leading zeroes or alter long values. Format the postal-code column as text before saving. Review “not found” rows rather than automatically treating them as invalid addresses because postal datasets can lag official changes and special-use codes may not be represented.
Privacy and scale
This browser form is intended for small operational checks. It does not require names, street addresses or customer details, and uploaded files are not saved by the application. For repeated automated validation, use a scoped API key and send only the minimum postal fields needed. Larger commercial workflows should retain their own audit trail and verify critical shipping addresses against the relevant national postal operator.
Understanding the three result states
A documented format result evaluates the code’s character arrangement for the selected country. A snapshot result checks whether the normalized country-and-code pair exists in the active import. A locality or deliverability decision requires additional address information. Keep those states separate in downstream systems; combining them into one “valid” flag hides important uncertainty.
Safe spreadsheet handling
Define the postal column as text before entering or importing data. Preserve leading zeroes, spaces and hyphens. Export with clear headers and inspect a sample after opening the file in the target application. Spreadsheet software can reinterpret codes as numbers, dates or scientific notation even when the source database was correct.
Retain the original value beside the normalized output. Do not silently pad, truncate or strip every non-digit character. Transformations must be country-aware and reviewable.
Reviewing exceptions
“Not found” can mean wrong country, input damage, a new or special assignment, or a gap in the public snapshot. Confirm valuable records with the national postal operator or carrier. “Format not verified” means the site has no active source-backed national pattern; it does not mean the address is wrong.
For shared postal codes, inspect the full postal result and compare the supplied locality. The batch form intentionally avoids choosing one arbitrary place.
Moving to automation
Repeated workflows should use the versioned API with a hashed key, daily quota and restricted origins where browser access is required. Send only country and code when that is all the check needs. Record request identifier, source metadata and outcome, but avoid placing complete customer addresses in general logs.
Public batch limits protect shared-hosting performance and prevent the utility from becoming an open bulk service. Paid access remains disabled until pricing, terms, payment and support workflows are actually configured.
Always review critical delivery records before dispatch.
Keep the source snapshot date with exported results so a later review can reproduce the outcome.
Archive only the minimum validation fields required for review, and remove temporary exports according to the organisation’s retention policy after corrections are completed.