| Business | Phone |
| Clay County Equalization Dir 211 W Main St, Vermillion 57069 | (605) 677-7140 |
| Clay County Extension Office 515 High St, Vermillion 57069 | (605) 677-7111 |
| Clay County Highway Shop 45969 Timber Rd, Vermillion 57069 | (605) 677-7149 |
| Clay County Register Of Deeds 211 W Main St # 202, Vermillion 57069 | (605) 677-7130 |
| Clay County Veterans Svc 211 W Main St # 203, Vermillion 57069 | (605) 677-7145 |