Working as an Agent in Collin County, TX: Cities and Local Checks
Short answer. Collin County is the sixth most populous county in Texas, and its biggest cities do not stop at the county line. Frisco, Plano, Prosper and Celina all reach into Denton County. For an agent, that turns "which county is this address in?" into the first question on every file.
Collin County in numbers
The 2020 Census counted 1,064,465 people in Collin County, up 36.1% from 2010. The county covers 886 square miles, and its county seat is McKinney.
That is a large, busy market with many agents already working it. Your edge comes from your systems and follow-up, not from the map.
Cities that cross the county line
Four Collin County cities we cover also sit partly in Denton County: Frisco, Plano, Prosper and Celina. Plano has only a small piece in Denton County. Frisco, Prosper and Celina are split in a way that matters.
The county decides which appraisal district and which taxing units apply to a property. Two homes on the same street name can sit in different counties. Look up each address before you quote anything about taxes.
- Frisco: Collin and Denton, with up to four school districts
- Plano: mostly Collin, a small part in Denton
- Prosper and Celina: both split between Collin and Denton
Fast growth brings special districts
Celina alone grew 24.6% in the year to July 2025, the fastest of any U.S. city over 20,000 people, according to Census Bureau estimates. New neighborhoods on that kind of growth often carry a MUD or a PID. Both change what a buyer pays and what a seller must hand over before the contract.
Our Prosper and Celina page walks through the notices.
Cities in Collin County on our coverage map
These are the Collin County areas where we are welcoming agents.
Agents in Collin County
On September 29, 2026, the Texas Real Estate Commission's public license data listed 8,176 active sales agents and 1,643 active individual brokers with a Collin County address on their license record.
This counts license records. It does not show who is working full time or how much business there is, so read it as background, not as a measure of competition. TREC's data has no city field, so we cannot split it by city.
Source: TREC Broker and Sales Agent License Holder Information, Texas Open Data Portal
The housing stock in Collin County
| Collin County | |
|---|---|
| Population (5-year estimate) | 1,163,337 |
| Housing units | 437,396 |
| Homes built since 2010 | 33% |
| Homes built before 1990 | 10% |
| Median year built | 2003 |
| Owner-occupied homes | 65% |
| Vacant housing units | 4.7% |
| Median home value | $475,600 |
| Median gross rent | $1,859 |
Source: U.S. Census Bureau, American Community Survey 5-year estimates, 2020 to 2024. These are estimates with margins of error, and 5-year figures lag the newer city estimates quoted elsewhere on this page.
Where to look it up
Search the property address on the appraisal district site to see which county tax roll it sits on. Check it on every file.
- Collin Central Appraisal District
- School district: use the district's own address lookup for the exact address
Common questions
What is the county seat of Collin County?
McKinney.
Is Frisco in Collin County or Denton County?
Both. Frisco lies in Collin and Denton counties, so check the county for each address.
Where can I see current county housing numbers?
The Texas Real Estate Research Center publishes housing activity by county. Use its Collin County page for current figures rather than a number from an article.
Sources
- Collin County, Texas (Wikipedia, citing the U.S. Census Bureau)
- Frisco, Texas (Wikipedia, citing the U.S. Census Bureau)
- Plano, Texas (Wikipedia, citing the U.S. Census Bureau)
- Prosper, Texas (Wikipedia, citing the U.S. Census Bureau)
- Celina, Texas (Wikipedia, citing the U.S. Census Bureau)
- Texas Tribune: Census Bureau 2025 city population estimates (May 14, 2026)
- Texas Real Estate Research Center: Collin County housing activity
- U.S. Census Bureau, American Community Survey 5-year estimates, 2020 to 2024 (via Census Reporter)
Education only. Not legal, tax or financial advice. Population figures are U.S. Census Bureau counts or estimates as reported by the sources above. Confirm licensing and disclosure rules with the Texas Real Estate Commission and your broker.