ZIP Express Lookup

Searching by ZIP code

If you already have a five-digit code, type it into the quick lookup box and press Enter. You will be taken directly to that code's profile page, which carries around 250 data points covering population, income, housing, commuting and geography. If the code does not exist — and many five-digit combinations do not — you will see a short message rather than an error.

Searching by city or place name

Most US cities are served by more than one postal code. Larger ones are served by dozens: New York City alone has well over a hundred. Entering a city name returns every code assigned to that place, sorted with the most populous first. This is usually the fastest way in when you know roughly where you mean but not the exact code.

Bear in mind that place names repeat across the country. There are more than forty distinct Springfields with their own postal codes. The results list shows the state alongside each result so you can pick the right one.

Searching by partial code

ZIP codes are geographically ordered. The first digit represents a broad region of the country, running roughly from 0 in New England up to 9 on the West Coast. The first three digits identify a sectional center facility — the regional sorting hub that processes mail for that area. Entering one to four digits returns everything starting with them, which is a useful way to explore a region you are unfamiliar with.

Using the advanced form

The advanced form above lets you combine criteria. Fill in only the fields that matter and leave the rest blank; the conditions combine, so specifying a place name and a state narrows to results matching both. A few examples of what it is good for:

• Finding every postal code in a specific state whose place name contains a particular word
• Narrowing an ambiguous city name to the correct state
• Listing codes within a single time zone, which is useful when scheduling deliveries or calls
• Confirming that a code you have been given actually belongs to the city you expect

Reading the results

Each result shows the code, the primary place name, the state, and the population where one is published. Codes marked non-residential have no measured population — they are PO Box clusters or codes assigned to a single high-volume recipient. There are 7,848 of them in the United States, and their pages explain what they are rather than showing a population of zero.

ZIP stands for Zone Improvement Plan. The system was introduced by the US Post Office Department in 1963 to speed up mail sorting as volumes grew beyond what manual routing could handle. The five-digit format has been in continuous use since, with the optional four-digit extension — ZIP+4 — added in 1983 to identify a specific block, building or even a single high-volume recipient.

Mail and delivery

The original purpose remains the main one. Postal codes let automated sorting equipment route a letter through the network without a human reading the address. Courier and logistics companies use the same codes for their own routing, and most shipping calculators price by origin and destination code.

Commerce and taxation

Online retailers use postal codes to calculate shipping costs and, in the United States, to determine sales tax. This is less reliable than it sounds: tax jurisdictions do not align neatly with postal boundaries, and a single ZIP code can span more than one tax rate. Retailers with serious compliance requirements use address-level rather than ZIP-level tax determination.

Insurance and risk pricing

Insurers price auto, home and health policies partly by postal code, because claim rates, theft rates and natural hazard exposure vary geographically. This is why two otherwise identical drivers a few miles apart can be quoted noticeably different premiums.

Demographic and market research

Because the Census Bureau publishes statistics for ZIP Code Tabulation Areas, postal codes have become a standard unit for market analysis, site selection and academic research. Businesses use them to decide where to open, what to stock and whom to advertise to. It is worth knowing that these statistics describe the Census approximation of a postal code, not the postal code itself.

Public administration

Government agencies use postal codes to route benefits, organise service areas, allocate funding and publish reporting. Emergency services use them alongside more precise systems, since a postal code alone is too coarse for dispatch.

Everyday identification

Postal codes are also used as a lightweight identity and location check — verifying a card at a fuel pump, confirming a delivery area, or filtering search results to a local area. In these contexts nothing is being posted at all; the code is simply a compact way to say roughly where you are.

The five digits are not arbitrary. Reading left to right, they narrow the geography:

• First digit — a group of states, numbered roughly west from the northeast. 0 covers New England and Puerto Rico; 9 covers California, Oregon, Washington, Alaska and Hawaii.
• Second and third digits — together with the first, these identify a sectional center facility, the regional hub that sorts mail for a cluster of surrounding post offices.
• Fourth and fifth digits — the specific post office or delivery area served by that facility.

There are four broad types of code. Standard codes cover ordinary geographic delivery areas and make up the great majority. PO Box codes serve only post office boxes at a particular facility. Unique codes are assigned to a single high-volume recipient — a large corporation, a university, a government agency. Military codes serve overseas armed forces addresses. Only standard codes have meaningful residential populations, which is why 7,848 US codes on this site carry no demographic data.

Our database holds 973,150 postal codes across 121 countries alongside the US set. Select a country from the dropdown, or leave it on Any country and we will search everything at once.

International results appear as information cards rather than links, because they do not have their own pages. Each card shows the postal code, the primary place name, any additional localities sharing that code, the region or province, the country, coordinates and time zone.

Why only US codes get full profiles

The depth on our US pages comes from the Census Bureau's American Community Survey, which publishes income, housing, education and commuting statistics for ZIP Code Tabulation Areas. Very few countries produce anything equivalent at postal-code granularity. Building international pages on the data we actually hold would mean a map pin and a coordinate pair — which is what the card already gives you, without pretending to be more.

Formats vary a lot

Canada uses six alphanumeric characters in a letter-digit-letter pattern. The United Kingdom uses a variable-length alphanumeric format where the outward code identifies a postal district and the inward code narrows to a street or building. The Netherlands uses four digits plus two letters. Japan uses seven digits. Ireland's Eircode assigns a unique code to every individual address. Our search accepts them as entered — there is no single format to normalise to.

Coverage is uneven

Some countries in the dataset have thousands of codes; a handful have only one. This reflects what national postal authorities publish openly rather than any judgement on our part. Mexico and India in particular list many localities under a single code, so we group them: the card shows the primary place and notes how many others share it.