| Business | Phone |
| Collin County 199th District 210 S Mcdonald St 220, Mckinney 75069 | (972) 548-4415 |
| Collin County 219th District 210 S Mcdonald St, Mckinney 75069 | (972) 548-4402 |
| Collin County 296th District 210 S Mcdonald St 424, Mckinney 75069 | (972) 548-4409 |
| Collin County 366th District 210 S Mcdonald St 514, Mckinney 75069 | (972) 548-4570 |
| Collin County Administration 210 S Mcdonald St 540, Mckinney 75069 | (972) 548-4601 |
| Collin County Agriculture Svc 210 S Mcdonald St, Mckinney 75069 | (972) 548-4233 |
| Collin County Agriculture Svc 825 N Mcdonald St # 150, Mckinney 75069 | (972) 548-4233 |
| Collin County Building Mntnc 4600 Community Blvd, Mckinney 75071 | (972) 547-5300 |
| Collin County Commissioners 210 S Mcdonald St 626, Mckinney 75069 | (972) 548-4631 |
| Collin County Constable 200 S Mcdonald St 220, Mckinney 75069 | (972) 548-4419 |
| Collin County Information Tech 210 S Mcdonald St 510, Mckinney 75069 | (972) 548-4503 |
| Collin County District Atty 210 S Mcdonald St 324, Mckinney 75069 | (972) 548-4323 |
| Collin County Elections 2010 N Redbud Blvd 102, Mckinney 75069 | (972) 633-3200 |
| Collin County Engineering 210 S Mcdonald St, Mckinney 75069 | (972) 548-4652 |
| Collin County Equipment Svc 700 Wilmeth Rd, Mckinney 75069 | (972) 548-3734 |
| Collin County Farm Museum 7117 County Road 166, Mckinney 75071 | (972) 548-4793 |
| Collin County Jury Clerk 210 S Mcdonald St, Mckinney 75069 | (972) 548-4315 |
| Collin County Justice Of Peace 210 S Mcdonald St, Mckinney 75069 | (972) 548-4125 |
| Collin County Juvenile Detntn 200 S Mcdonald St, Mckinney 75069 | (972) 548-4798 |
| Collin County Juvenile Detntn 4700 Community Blvd, Mckinney 75071 | (972) 547-5400 |
| Collin County Juvenile Probtn 1800 N Graves St # 300, Mckinney 75069 | (972) 548-4130 |
| Collin County Medical Examiner 700 Wilmeth Rd B, Mckinney 75069 | (972) 548-3775 |
| Collin County Passport Svc 210 S Mcdonald St 300, Mckinney 75069 | (972) 548-4381 |
| Collin County Purchasing Dept 210 S Mcdonald St, Mckinney 75069 | (972) 548-4118 |
| Collin County Substance Abuse 825 N Mcdonald St 110, Mckinney 75069 | (972) 548-5570 |
| Collin County Vehicle Rgstrtn 1434 N Central Expy, Mckinney 75070 | (972) 547-5000 |
| County 4-H & Youth 210 S Mcdonald St, Mckinney 75069 | (972) 548-4232 |
| County 4-H & Youth 825 N Mcdonald St # 150, Mckinney 75069 | (972) 548-4232 |
| Guardian Ad Litem Child Spprt 301 W Louisiana St, Mckinney 75069 | (972) 562-4500 |
| Human Resources 210 S Mcdonald St 612, Mckinney 75069 | (972) 548-4606 |