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Updated 2025 Tax Year

Sully County
Property Tax Guide

Everything you need to know about property taxes in Sully County, SD. Rates, due dates, exemptions, and how it affects your monthly payment.

10 Official Sources
8 min read
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Quick Facts
Tax Rate
Approximately 0.50% effective rate, varies by taxing district (school, fire, etc.)
Exemptions
5+ Available
Section 1

How Property Tax Works

Sully County, South Dakota operates on a property tax system that serves as the primary funding mechanism for local government services, including schools, roads, emergency services, and county operations. Property owners in Sully County pay an effective tax rate of approximately 0.50% based on the assessed value of their property, though this rate can vary significantly depending on your specific location within the county due to special taxing districts such as school districts, fire districts, and other local improvement districts.

The county assesses property at its full market value without a statewide assessment cap, meaning your assessed value should reflect the current market value of your property. Property taxes in Sully County are collected annually, with the tax year running from January 1st through December 31st. It's important to understand that your actual tax rate depends on the combination of county levy, school district levy, and any applicable special district assessments that apply to your specific property location.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
County General Levy~0.20%Funds county operations, roads, law enforcement
School District Levy~0.25%Varies by school district within county
Special Districts~0.05%Fire districts, library districts, other local services
Total Effective Rate~0.50%Combined rate for FY 2025-2026

Note: These rates apply to the 2025 levy year and vary by specific location within Sully County. Properties in different school districts or special taxing districts will have different total rates. Contact the Sully County Director of Equalization at (605) 258-2535 for your specific district rates.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Sully County, property taxes are due in two installments:

Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental taxes in Sully County are triggered when there are changes in property ownership, new construction, or improvements that increase the assessed value of a property during the tax year. These taxes are calculated based on the difference between the old and new assessed values, prorated for the portion of the tax year the higher value applies.

For example, if you complete a $50,000 home addition in July, and your property is reassessed from $300,000 to $350,000, you would owe supplemental taxes on the $50,000 increase for the remaining 6 months of the tax year. Using the 0.50% tax rate, this would result in approximately $125 in supplemental taxes ($50,000 × 0.005 × 0.5 years). Supplemental tax bills are typically issued within 60 days of the assessment change and are due within 30 days of the bill date.

Example Calculation

Example 1: $300,000 Property

  • Assessed Value: $300,000
  • Less: Homestead Credit (if applicable): -$0 (requires application)
  • Net Taxable Value: $300,000
  • Annual Tax: $300,000 × 0.005 = $1,500
  • Monthly Escrow: $125

Example 2: $600,000 Property

  • Assessed Value: $600,000
  • Less: Homestead Credit (if applicable): -$0 (requires application)
  • Net Taxable Value: $600,000
  • Annual Tax: $600,000 × 0.005 = $3,000
  • Monthly Escrow: $250

Example 3: $1,000,000 Property

  • Assessed Value: $1,000,000
  • Less: Available Tax Credits: -$0 (most require application)
  • Net Taxable Value: $1,000,000
  • Annual Tax: $1,000,000 × 0.005 = $5,000
  • Monthly Escrow: $417

Note: Tax credits shown require annual application and approval. Contact the Sully County Assessor for available programs and application requirements.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Sully County require property tax escrow accounts to ensure timely payment of property taxes. Your lender will collect approximately 1/12th of your annual property tax bill with each monthly mortgage payment, depositing these funds into an escrow account. The lender then pays your property taxes directly to Sully County when they become due on November 30th each year.

Lenders typically conduct an annual escrow analysis to ensure adequate funds are collected, which may result in adjustments to your monthly payment. If your property taxes increase due to reassessment or rate changes, your monthly escrow payment will be adjusted accordingly. Property owners can verify their tax payments and balances by contacting the Sully County Treasurer at (605) 258-2534 or checking online payment records. If you pay taxes directly without escrow, ensure payments are made by the November 30th deadline to avoid penalties and interest charges.

How HonestCasa Helps
  • Understand whether your escrow is set correctly
  • See how rising taxes will change your monthly payment
  • Plan ahead instead of being surprised by "shortage" letters
Section 6

Frequently Asked Questions

Q: When are property taxes due in Sully County for the current fiscal year? A: Property taxes for the 2025 tax year are due by November 30, 2025, with a final deadline of December 31, 2025. Late payments incur penalties and interest.

Q: What tax credits are available and do they require application? A: Most tax credits in Sully County require annual application, including disabled veteran credits and certain agricultural credits. Contact the County Assessor at (605) 258-2535 for available programs and application deadlines.

Q: How does the Homestead credit work? A: South Dakota's homestead credit limits annual assessment increases rather than reducing market value. This credit requires application and caps assessment growth to help long-term residents. Contact your county assessor for eligibility and application requirements.

Q: When are properties reassessed in Sully County? A: Sully County conducts property assessments annually, with new values typically established by March 1st for the current tax year. Property owners receive assessment notices and have appeal rights.

Q: What are the penalties for late property tax payments? A: Late payments incur interest charges and penalties. Taxes become delinquent after December 31st, with additional collection costs and potential tax deed procedures for extended non-payment.

Q: Can I pay property taxes online in Sully County? A: Contact the Sully County Treasurer's office at (605) 258-2534 for current online payment options and accepted payment methods.

Q: How do special district taxes affect my bill? A: Special districts for schools, fire protection, and other services add to your base county tax rate. Your total rate depends on which districts serve your property location.

Q: How do I appeal my property assessment? A: Assessment appeals must be filed with the County Board of Equalization by specific deadlines, typically within 30 days of receiving your assessment notice. Contact the County Assessor for appeal forms and procedures.

Verified Sources

Backed by 10 Official Government Sources

Every fact in this guide is sourced from official county, state, and federal documents.

01
Tax Doc
Tax-Rates.org — The 2024-2025 Tax Resourcemylrc.sdlegislature.gov
02
Tax Doc
Calculating the Dollars Needed to Reduce Property Taxesmylrc.sdlegislature.gov
03
County
12.05.2023.pdf - Sully County, South Dakotasully.sdcounty.gov
04
County
Sully County, SD Real Estate & Property Data | ATTOMpropertynavigator.attomdata.com
05
County
Sully County Property Records | Owners, Deeds, Permitssouthdakota.propertychecker.com
06
State
State Wise Property Tax Deadlines 2025 | Key Due Datesncscorpglobal.com
07
Tax Doc
Tax Exempt Propertymylrc.sdlegislature.gov
08
County
Codified Law 28-13-32 - County commissioners' objections to ...sdlegislature.gov
09
County
County Treasurers | South Dakota Department of Revenuedor.sd.gov
10
Joe Fanger Jerry Richards Greg Yackley Caleb Shepherd Paula ...sully.sdcounty.gov
All sources verified as of 2025 Tax Year

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