Duncan ZIP Code Coverage at a Glance
USPS is the source for a current Duncan ZIP code result. Duncan research supports 73533 as the principal Duncan street-delivery lead. Official legacy destination material also lists 73534 under Duncan, but the available Duncan research did not verify its current street-delivery or PO-box classification. The safe way to use both Duncan labels is to enter a complete address in the USPS lookup and preserve the result date. Nearby Census ZCTAs are not additional Duncan mailing ZIPs.
| ZIP code | Areas covered | Post office | Current Duncan note |
|---|---|---|---|
| 73533 | Principal Duncan street-delivery lead | Duncan Post Office, 802 W Willow Ave | Validate every complete address because postal coverage is not the same as city limits. |
| 73534 | Duncan postal designation in official legacy destination tables | Duncan postal route | Current street or PO-box classification was not verified in the research and needs a USPS City State Product check. |
The Duncan research found no official Duncan coverage for 73599. It also found no basis to call 73055, 73434, or 73529 Duncan delivery ZIPs merely because they appear in a nearby Census profile. A smaller verified Duncan table is more useful than an expansive one built from statistical proximity.
Validate a Duncan ZIP Code by Address
The USPS ZIP Lookup accepts a Duncan residential or corporate street, city, and state, then returns the ZIP assigned to the entered Duncan address. USPS says that a returned result does not guarantee an actual physical location. That limitation is important for Duncan research. The tool validates a Duncan address format for postal use. It does not identify a person, establish occupancy, prove a Duncan city boundary, or turn a ZIP into a parcel description.
| USPS lookup field | Duncan ZIP-code use | Result limit |
|---|---|---|
| Street address | Supplies the complete Duncan delivery-address input. | Use a known Duncan address; do not use the tool to generate people or addresses. |
| City | Pairs the address with Duncan for postal validation. | A USPS city label is not a city-limit determination. |
| State | Completes the Duncan, Oklahoma address input. | It does not substitute for the Duncan parcel’s legal description. |
| Returned ZIP | Records the current ZIP assigned to that complete Duncan input. | USPS says the response does not guarantee an actual physical location. |
For a Duncan mailing question, use the complete street address and save the Duncan result with the date checked. For a current list or raw validation file, USPS City State Product is the monthly ZIP, city, and county source noted in the research. Compare a returned Duncan ZIP with that current product when the distinction matters. Do not replace that Duncan verification with a commercial ZIP summary or a nearby Census map.
- ZIP code
- A postal routing code assigned to an address or delivery arrangement, not a municipal boundary.
- ZIP+4
- An added four-digit routing segment that narrows delivery handling beyond the basic five-digit ZIP code.
- PO-box ZIP
- A postal designation used for post-office boxes; its classification must be confirmed from current USPS information.
- Carrier route
- A USPS delivery grouping used for mail handling, not a neighborhood or resident roster.
Note: Preserve the exact address entered and the date returned when a postal result is used as a research lead.
Duncan ZIP Code Directory Boundaries
Duncan city, Stephens County, USPS city, ZIP, Census ZCTA, precinct, school district, and parcel boundaries can diverge around the same Duncan address. A ZIP is a mail-delivery designation. A Duncan city limit is a legal municipal boundary. A Duncan parcel follows the assessor and recorded land description. A ZCTA is the Census Bureau’s statistical approximation of ZIP geography. None of those labels should be silently substituted for another.
This matters most at a Duncan edge or when a Duncan address has changed form. A complete address could use a Duncan mailing designation while sitting outside the municipal limit, or a Duncan city record could use a civic address that differs from the postal format. For a Duncan property or street-history question, validate USPS first, then reconcile Duncan city or county E911 information, assessor situs, parcel, recorded legal description, and a historic map when needed.
Search Duncan Records With a ZIP Code
A ZIP can narrow a Duncan address-validation task, but it is not a universal search field across Duncan records. The Duncan Assessor’s live form was not text-readable during research, so no ZIP filter should be promised there. DataScout showed an assessor-linked map, Property Owner and Tax District labels, but a live Duncan parcel capture is still needed to confirm its search controls. The Duncan Clerk index supports land-description and party fields rather than a documented ZIP search. Use the ZIP to validate the Duncan address, then continue with the field the Duncan record system actually supports.
- Enter the complete Duncan address in the USPS lookup and record the returned Duncan ZIP with the retrieval date.
- For a Duncan parcel question, contact the Stephens County Assessor in Duncan for the parcel number, situs, tax district, and legal description. Confirm current online search options before relying on any filter.
- Search the Stephens County Clerk land index in Duncan with the legal description, party name, book/page, instrument number, date, or addition/block/lot fields that fit the known record.
- Use an assessor-linked map to orient the parcel, then compare it with the county record and deed. For a street-by-street land trail, continue with the Duncan street directory.
The Oklahoma Voter Portal is primarily an individual’s identity-gated service. Restricted Election Data Warehouse files have eligibility and signed-use conditions, so a ZIP should not be framed as a way to create a public list of people.
Duncan ZIP Code Parcel Context
Once USPS returns a ZIP, the county record trail becomes address and parcel based. The Assessor is at 101 S 11th Street, Room 210, with 580-255-1542 listed in the research. It is the first official route for a parcel number, legal description, assessed owner/address label, tax district, exemptions, valuation, and E911 addressing lead. A situs address may differ from a tax mailing address, so do not use a ZIP alone to reconcile that difference.
The County Clerk land portal can then search grantor or grantee names, business names, party type, book/page, series, instrument number or type, date range, legal description, quarter-quarter, section, township, range, addition, block, and lot. Its research-reported coverage begins with images in January 1991 and indexed records in February 1996. The official Clerk record, not a parcel label, is the stronger source for a land conveyance.
| System | ZIP-related use | Limit |
|---|---|---|
| USPS Lookup | Checks the ZIP returned for a complete entered address. | Does not prove a person is at the address. |
| Assessor | Reconciles the address to an assessment parcel and legal description. | Live online filter fields need confirmation. |
| County Clerk | Searches the parcel’s recorded instrument trail. | Uses party and land-description fields, not a documented ZIP filter. |
| Census | Supplies aggregate geographic context. | A ZCTA is not a postal-boundary record. |
Duncan ZIP Code Geography in Numbers
The Census QuickFacts profile for Duncan provides citywide context, not a ZIP-level resident list. It reports 22,692 people in the 2020 Census, a 2025 estimate of 23,238, 42.96 square miles of land, and 9,492 households. These figures describe Duncan city as an aggregate. They should not be divided across a postal code or assigned to a particular mailing route.
QuickFacts also displayed nearby ZCTAs including 73055, 73434, 73529, and 73533. Their presence in a profile does not mean all are Duncan mailing ZIPs or that every Duncan address uses one of those labels. Use Census for population, land, and household context. Use USPS for the answer to a complete-address ZIP question.
Separate Duncan ZIP Codes From ZCTAs
A Census ZCTA is a statistical approximation created for tabulating data. It is not the USPS delivery map, and it cannot establish the ZIP for a particular Duncan street. The difference is not merely technical. A static ZIP list built from nearby ZCTAs can wrongly pull in addresses that USPS does not designate as Duncan or omit a valid postal designation that should be tested address by address.
For a historical or parcel question, use a two-part record note: the complete address and its USPS result on one line, then the city, parcel, or Census geography on another. The separation makes later verification possible. It also avoids treating demographic aggregates as person-level evidence.
Note: The research did not capture an official Duncan-area ZIP-boundary artifact or current City State Product rows for 73533 and 73534.
Duncan ZIP Code Directory Privacy Limits
A ZIP code does not authorize a broad people search. Voter, court, vital, and address-confidentiality rules still control the records held by those custodians. The Oklahoma Voter Portal supports a voter’s own registration services with identity checks. Election Data Warehouse access is limited to qualifying requesters who complete the required form and attest to statutory conditions. Protected voter categories and Address Confidentiality Program participants have additional restrictions.
Use the minimum identifying information needed for the source question. Do not combine a USPS result, assessment owner label, voter material, obituary information, and unrelated records into a new profile. If a public record has redacted or protected portions, request only the existing record that is relevant and preserve the custodian’s source, date, and access note.
Confirm Duncan ZIP Code Service
USPS lists the Duncan Post Office at 802 W Willow Ave, FL100, Duncan, OK 73533-9998, with 580-255-7226. Research observed Monday through Friday hours of 8:30 to 4:30, Saturday hours of 9:30 to 11, and carrier, general-delivery, and PO Box-related services. Postal hours and services can change, so verify directly before a visit.
The USPS location page is useful for service and contact verification. The address-to-ZIP lookup remains the appropriate tool for testing a complete street address.
Request Duncan ZIP Records by Custodian
If a ZIP-associated question needs more than postal validation, ask the office that holds the particular existing record. A parcel or tax-district question belongs with the Assessor. A deed, mortgage, lien, or plat question belongs with the County Clerk. A municipal address, planning, permit, or code question should name the address and date range for the City Clerk or the relevant city department. Research found no public city permit-result index, so a narrow request is more useful than a request for a new ZIP-based compilation.
Oklahoma’s Open Records Act, Title 51 O.S. §§24A.1–24A.31, covers reasonable access to existing records subject to exemptions and redactions. The state open-records guidance recommends identifying the record, date range, geography, and preferred format. Ask for an electronic copy and fee estimate where appropriate. A records request does not override voter, court, vital-record, or confidentiality restrictions.