Is a parcel number the same as my street address?

No. A street address is assigned by the post office or local addressing authority and can change with renumberings or annexations. A parcel number is assigned by the county assessor and identifies the legal parcel, which is more stable. A vacant lot has a parcel number but no address; a high-rise has one parcel number but dozens of unit addresses.

What is the difference between APN, PIN, and PID?

APN (Assessor's Parcel Number) is the term most California, Arizona, Nevada, and southern-state counties use. PIN (Property Index Number) is the term Illinois, Indiana, and several Midwest states use. PID (Property Identification Number) is common in Texas and the Plains states. They all mean the same thing — the unique number the county uses to track that parcel — but the field name varies on assessor websites and GIS data layers.

Can I find a parcel number if I only have the owner's name?

Sometimes, depending on the county. About 60 percent of indexed counties expose the owner or taxpayer name as a searchable field on their public REST layer. The remaining 40 percent index by parcel ID and address only — owner search requires the county assessor's site. The UrbanKit atlas notes which counties expose owner-name search.

Why is my parcel number formatted differently than my neighbor's in another state?

Every county designs its own parcel-number format. Some encode the township-range-section into the number (common in Midwest grid-survey states); some encode the assessor's map book and page (common in California); some are arbitrary integers (common in Texas account-number systems). There is no national standard. Within a single county, every parcel has a unique number; across counties, the same number can repeat.

Do I need a parcel number to mail a public notice?

Yes — radius public-notice mailings use parcel polygons to determine which owners receive notice, and those polygons are keyed by parcel number. The mailing list is generated by selecting parcels inside the buffer ring, then joining to owner names and mailing addresses. The address on the envelope is the OWNER'S mailing address, which is often different from the parcel's situs (property) address — especially for absentee landlords.

What if my county isn't in the UrbanKit atlas?

The Find My Parcel Number tool will still detect your state and county via the Census Geocoder, then hand you off to a search on your County Assessor's website. You'll just look up the parcel number there instead of in our tool. We are growing the atlas continuously and accept contributed county REST URLs through the contact page.

Will my parcel number change if I sell the property?

Generally no. Parcel numbers persist across ownership transfers — only the deed and owner records update on transfer. Parcel numbers DO change when the underlying parcel is split, merged, or remapped by the assessor (rare events, usually accompanying subdivision or boundary-line adjustments). The parcel number on your closing documents will match the number on your tax bill ten years later in the typical case.

How to Find Your Parcel Number from Your Address (2026 Guide)

By Leo Yong · Last updated May 25, 2026 · 12 min read

Your parcel number — also called an APN, PIN, PID, or tax parcel ID depending on the state — is the unique identifier your county assigns to your property. You need it any time the county or a government form asks about a specific piece of land: property tax payments, building permits, deed transfers, public-notice mailings, refinance applications, even setting up trash service in some places.

The annoying part is that no two counties format the number the same way, and the county assessor's website is rarely the first result you hit when you search for it. This guide walks through three reliable ways to get the parcel number from a street address, including a free tool that handles the lookup automatically for 117 indexed counties across 39 states.

The fastest path: if you just want the number now, paste your address into UrbanKit's Find My Parcel Number tool. The tool resolves your address to a state and county via the U.S. Census Geocoder, then — if your county is in the indexed atlas — queries the county's public ArcGIS REST endpoint and returns the parcel number on the page. No account, nothing stored.

What is a parcel number, and why does it matter?

Every U.S. county maintains a cadastral system — a map of every legally distinct piece of land, with a unique identifier per parcel. The number is assigned by the county assessor (or sometimes the recorder, or the property appraiser, depending on the state). It anchors:

Property tax assessment. Your tax bill is keyed by parcel number; the county uses it to look up assessed value, exemptions, payment status, and the responsible taxpayer.
GIS layers and mapping. The county's parcel polygons in ArcGIS or QGIS are keyed by parcel number; you can spatially query — "what parcels are within 500 feet of this address?" — and get back a list of parcel numbers, which you then join to owner data for a notice mailing.
Title and deeds. When you bought your house, the deed referenced the parcel number. When you refinance or sell, the new deed will too.
Permits and land-use cases. Building permits, variance requests, zoning appeals, septic permits — they all reference the affected parcel by number, not by address.

For background on the identifier itself — the difference between APN and PIN, why they sometimes have leading zeros, what to do when your spreadsheet eats them — the APN explainer has a deeper treatment. This article is focused specifically on the lookup: address in, parcel number out.

Three ways to find your parcel number

Method 1: Use the Find My Parcel Number tool (fastest)

UrbanKit's Find My Parcel Number tool handles the lookup end-to-end for any property in an indexed county. The flow:

Type your address (street, city, state — ZIP is optional but helps).
The tool calls the U.S. Census Geocoder through a stateless proxy. The Geocoder returns the normalized address, the state, and the county FIPS code.
The tool checks the FIPS code against the UrbanKit atlas (117 counties across 39 states). If your county is indexed, it queries the county's public ArcGIS REST endpoint with the normalized street portion of your address and returns the parcel number directly, displayed prominently on the page.
If your county isn't yet indexed, the tool still confirms your state and county and links you to a Google search for the County Assessor's parcel-search page.

This is the right starting move for most people, because it works in two clicks (paste, submit) and tells you immediately whether your county supports the automated lookup. If it does, you have your number. If it doesn't, you've narrowed down which county to search.

Method 2: County Assessor or Property Appraiser website (most reliable)

Every U.S. county publishes a parcel viewer or parcel search on its assessor's, appraiser's, or treasurer's website. This is the canonical source — the county built it, the county updates it, the data on it is what the county uses for tax billing. If the automated tool returns an unexpected result, or if your county isn't indexed, the county's own site is the authoritative fallback.

The exact name and URL differ by state:

California: County Assessor (e.g., assessor.lacounty.gov, assessor.sonomacounty.ca.gov). Search by site address; returns APN.
Illinois: County Supervisor of Assessments or Tax Assessor (e.g., kanecountyassessments.org, cookcountyassessor.com). Search by address; returns PIN.
Texas: County Appraisal District — usually [county]CAD.org, e.g., HCAD.org for Harris, traviscad.org for Travis. Search by address; returns Geo ID or property ID.
Florida: County Property Appraiser (e.g., miamidade.gov/pa, bcpa.net for Broward). Search by address; returns folio number.
New York: County Real Property Tax Service Agency, or for NYC, the Department of Finance (www1.nyc.gov/site/finance). NYC uses BBL (borough-block-lot); upstate counties use SBL (Section-Block-Lot) or tax map ID.

If you don't know which county your property is in, the Find My Parcel Number tool above will tell you in one step, and then you can navigate to the county's site if you prefer the canonical source.

Method 3: County REST API (for developers and batch lookups)

If you need to look up many parcels programmatically — for a public-notice mailing list, a property data pipeline, a research dataset — most counties expose an ArcGIS REST FeatureServer or MapServer that you can query directly with HTTP. The UrbanKit Parcel REST API Atlas indexes 117 counties' endpoints, with the searchable field names per layer.

A typical query looks like this:

curl -s 'https://gistech.countyofkane.org/arcgis/rest/services/KanePINList/MapServer/0/query?where=UPPER(SiteAddress)%20LIKE%20UPPER(%27%25100%20N%20LAKE%20ST%25%27)&outFields=PIN,TaxName,SiteAddress&returnGeometry=false&f=json'

The Parcel Lookup tool is a browser frontend over the same REST pattern — useful if you want to test a county's endpoint without writing code. For deeper background on the REST query pattern itself, the ArcGIS parcel layer URL article covers how to find any county's endpoint manually.

State-by-state variations: same concept, different name and format

Below is a sketch of how the parcel number works in each region, by name, format, and the most common search-by-address field on the county's REST layer (if any). This is the kind of context that helps when you're staring at an unfamiliar assessor's site and trying to figure out which field is the one you need.

Region	Common name	Typical format	REST address field
California, Arizona, Nevada	APN (Assessor's Parcel Number)	10–12 digits, often `NNNN-NNN-NNN` (book-page-parcel)	`SitusAddress`, `SITUS_ADDR`, `street_address`
Illinois, Indiana, Wisconsin	PIN (Property Index Number)	14 digits, often `NN-NN-NNN-NNN-NNNN`	`SiteAddress`, `street_address`, `PROPSTNAME` (DuPage)
Texas	Geo ID or Property ID	13–15 digit account number; some counties also publish a separate "quick reference" Geo ID	`SitusAddress`, `Owner` (street fields vary widely)
Florida	Folio number or strap number	13-digit `NN-NNNN-NNN-NNNN` (section-township-range-suffix) or compressed 17-digit version	`SITE_ADDR`, `SITUS`
New York (NYC)	BBL (Borough-Block-Lot)	10 digits: `B-BBBBB-LLLL` (1 = Manhattan, 2 = Bronx, etc.)	City portal (`nyc.gov/digitaltaxmap`)
New York (upstate)	SBL or Tax Map ID	Varies; commonly section-block-lot dotted notation	`PRIMARY_OWNER`, `COUNTY_NAME`-filtered statewide RPS layer
Pennsylvania	Parcel ID	Varies by county; many use ward-block-lot or registry district codes	Allegheny WPRDC, county-specific viewers
Louisiana	Assessor parcel ID	Parishes (not counties); Orleans uses a Square/Lot system rooted in 18th-century French survey grids	Assessor websites per parish
Massachusetts, Vermont	Map-Lot or Town-Parcel	Town-as-parcel-unit; identifiers vary widely between municipalities, not standardized at county or state level	VCGI statewide (VT), municipal viewers (MA)
Virginia	GPIN / Parcel ID	Independent cities (38 of them) maintain separate parcel registries from surrounding counties	`GPIN`, `PARCEL_ID`

The takeaway from the variations: when you find a parcel number in one place and want to use it somewhere else, double-check that the system you're using understands the format. Pasting a 14-digit Illinois PIN into a California assessor's site will get you nothing; pasting an Orleans Parish Square/Lot identifier into a national real-estate API will silently fail. The county REST layer is the authoritative source for its own parcels' format.

What if your county isn't in the UrbanKit atlas?

The atlas indexes 117 counties as of mid-2026, which is roughly 4 percent of the ~3,100 U.S. counties. The selection biases toward higher-population counties and states with strong open-data programs. If your county isn't indexed, three options:

Use Method 2 (County Assessor website). Every county has one, even small rural ones. Search engines find them quickly: "[County name] [State] assessor parcel search".
Check if your state has a statewide parcel layer. A few states publish unified parcel layers that cover every county: Vermont (VCGI), Connecticut (a state-level service), Rhode Island (RIGIS), portions of New York via the statewide RPS layer. If yours does, the layer is already in the atlas under the state's slug.
Contribute your county. If you know the county's public ArcGIS REST URL, the contact page has a form to submit it. Once verified (we run a liveness probe), we add it to the atlas and the next release of the npm package @urbankitstudio/atlas picks it up.

Common mistakes when working with parcel numbers

Treating the parcel number as the address

The parcel number identifies the land. The address identifies a delivery point on the land. They drift apart: a parcel may have no address (vacant), one address, or many (a multi-unit building). For mailing, you want owner addresses, not parcel numbers. For zoning or tax research, you want parcel numbers, not addresses.

Losing leading zeros in spreadsheets

Most parcel numbers start with one or more zeros. Spreadsheets treat numeric-looking strings as numbers by default, which strips the zeros silently. Symptom: your 14-digit PINs become 13-digit ones and don't match anything. Fix: format the column as Text before pasting, or prepend a single quote (') to force text storage. When exporting from a county GIS layer, set the field type to string in your export options.

Searching for the wrong parcel number for split or merged parcels

Parcel numbers persist across ownership transfers but DO change when the assessor splits or merges parcels. If a property was subdivided in the last five years, the old parcel number may still appear in some title records but the new numbers are what the county uses now. The current REST layer always returns the current number; older title documents may carry the historical one.

Confusing parcel number with tax account number

In some states (notably parts of Texas), the county appraisal district maintains both a parcel ID (geographic) and a separate tax account ID (financial). They reference the same property but are different numbers in different systems. The tax bill and the GIS layer may not agree on which number is "the" parcel number — always check the field name on the source you're working with.

Assuming national uniqueness

Two different parcels in two different counties can have the same number. When you store parcel numbers in a database or share them in a report, always include the county (or at least the state) alongside. The combination of (state, county, parcel number) is unique; the parcel number alone is not.

For developers: how the address-to-parcel pipeline actually works

The Find My Parcel Number tool is a composition of three open services and one piece of glue we built:

U.S. Census Geocoder. Free, no API key. The endpoint geocoding.geo.census.gov/geocoder/geographies/onelineaddress takes an address and returns the matched address, the state FIPS, the county FIPS, the urban area, the census tract, and lat/lon. The Geocoder does not include a CORS header, so direct browser fetch is blocked — UrbanKit runs a stateless edge-function proxy that adds the CORS header for our origin and returns the upstream response unchanged.
FIPS-to-county lookup. The 5-digit county FIPS (state 2-digit + county 3-digit) is unique per U.S. county. The UrbanKit atlas's index file carries the FIPS on every indexed county. We do a hash-table lookup — O(1) — to find whether your county is one we cover.
County ArcGIS REST query. If your county is indexed, the tool builds a /query URL against the county's FeatureServer or MapServer with a LIKE-wildcard match on the address field (which varies per county; SiteAddress in Illinois, SITUS_ADDR in California, etc.), fetches the response from your browser, and parses out the parcel ID field and the matched record's attributes.

If you want to build something similar, the npm package @urbankitstudio/atlas exposes the indexed county metadata and the searchable-field schemas. Pair it with any geocoder (Census, Mapbox, Nominatim) and the same REST query pattern.

The bottom line

For most people, just paste your address into the tool and get your number. For developers building a pipeline, the Parcel REST API Atlas indexes the endpoints you need. For unusual cases — counties not yet indexed, historical parcel research, batch lookups for a notice mailing — the County Assessor's website is the authoritative source.

The parcel number is small data, but it's the key into every other property system you'll ever touch. Worth knowing how to find it once.