DIPOMEX and PostalKit, compared
This is the shortest comparison on the site, because the headline fact settles most of it: DIPOMEX costs nothing. If a postal code and its colonias is the whole of what you need, that is the answer, and the rest of this page is about the cases where it is not.
What DIPOMEX is
A free Mexican postal code API — the Directorio Postal Mexicano. You register for a key and call it; there is no paid tier to move up to, because there is nothing to pay for. Give a postal code and it answers with estado, municipio, código postal, colonias.
It publishes at this address:
api.tau.com.mx/dipomex
Side by side
| Item | PostalKit | DIPOMEX |
|---|---|---|
| Price | Free up to 100 requests a month, then from $149 MXN a month | Free, with no paid tier |
| To get started | An account and a token, no card | Registration for an API key |
| A postal code lookup returns | estado, municipio, ciudad and colonias with their settlement type | estado, municipio, código postal, colonias |
The row above says what each API documents returning. It is not a list of what the other one lacks — we could not reach the DIPOMEX documentation to check, so we are not going to characterise it.
Verified on August 17, 2026.
Where DIPOMEX is the better answer
It is free, and free is a feature. If you are filling in a checkout form — the customer types a postal code, you fill in the estado and the municipio and offer a list of colonias — DIPOMEX does that and charges nothing for it. There is no argument on this page that beats a price of zero for a job that is already done.
Nor is a free API a lesser one by definition. The underlying catalog is the same national file everyone reads, so on the questions both answer, they answer from the same source.
The other side
What you would be paying for
Everything below is the answer to “what does money buy here”, and it is worth reading as a list of things you may well not need.
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The rest of the hierarchy.
PostalKit publishes 21 endpoints across eight resource groups — postal codes, settlements, states, municipalities, localities, streets, geocoding and account. Listing the municipios of an estado, searching colonias by name, or paging every postal code in a municipio are calls rather than exports you assemble.
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A refresh you can audit.
The official source is re-checked on the first of every month, and nothing changes unless the source actually changed. GET /v1/account/db-version returns which version you are reading, so “is this current?” is a request rather than an email.
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Something to build a client from.
A published OpenAPI document and Postman collection, regenerated on every deploy, plus rate-limit headers on every response so your own retry logic has something to read.
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Someone whose job it is.
A free API is under no obligation to anyone. A paid one has a customer, which is the whole of the difference when something breaks on a Friday.
Which one to pick
Start free — with either of us. PostalKit’s free tier is 100 requests a month and asks for no card, which is enough to run your real addresses through both. If a postal code lookup answers your whole question, you have your answer and it costs nothing. Come back when the question gets bigger than one endpoint.
The same comparison against the other two: Copomex, Postalia. If you have not picked a provider at all yet, the SEPOMEX catalog guide covers the free official file first.