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Updated 2025 Tax Year

Sioux County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
Varies by location due to multiple taxing districts, 23.2% increase from previous year
Exemptions
4+ Available
Section 1

How Property Tax Works

Sioux County, North Dakota operates on an annual property tax system that funds essential local services including schools, roads, law enforcement, and county operations. Property taxes are calculated by applying local tax rates (called mill levies) to the assessed value of real property, which is determined by the county assessor based on market value.

For the 2025 tax year, Sioux County has experienced a significant 23.2% increase in property tax rates compared to the previous year. Actual tax rates vary considerably depending on your specific location within the county, as different areas may be subject to additional special taxing districts such as school districts, fire districts, and other local improvement districts. Property owners should expect effective tax rates that generally align with North Dakota's base rate of approximately 1% of assessed value, though individual bills may vary based on applicable credits and district-specific levies.

Section 2

What Makes Up Your Tax Bill

ComponentRate RangeDescription
County General LevyVariesFunds county operations, roads, law enforcement
School District LevyVaries by districtLocal school funding and bond payments
Township/City LevyVaries by municipalityMunicipal services and infrastructure
Special Assessment DistrictsVaries by locationFire protection, water, sewer, improvements
Total Effective Rate~1.0% - 1.5%Combined rate after 23.2% increase for FY 2025

Note: These rates apply to the 2025 levy year and vary significantly by specific location within Sioux County due to overlapping taxing jurisdictions. Contact the Sioux County Assessor's Office for exact rates applicable to your property's tax district.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Sioux 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 Sioux County are additional property tax assessments that occur when there are changes to property ownership, new construction, or improvements made after the annual assessment date. These taxes are calculated based on the difference between the old and new assessed values, prorated for the remaining months in the tax year.

Common triggers include purchasing a home, completing new construction, adding significant improvements like additions or major renovations, or correcting assessment errors. For example, if you complete a $50,000 home addition in March and your local tax rate is 1.2%, you would owe approximately $500 in supplemental taxes (($50,000 × 1.2%) × 10/12 months remaining in the tax year). Supplemental tax bills are typically issued within 60-90 days of the triggering event and have separate due dates from your regular annual property tax bill.

Example Calculation

Example 1: $300,000 Home

  • Assessed Value: $300,000
  • Homestead Tax Credit Applied: -$3,000 (estimated)
  • Net Taxable Value: $297,000
  • Tax Rate: 1.2%
  • Annual Tax: $3,564
  • Monthly Escrow: $297

Example 2: $600,000 Home

  • Assessed Value: $600,000
  • Homestead Tax Credit Applied: -$3,000 (estimated)
  • Net Taxable Value: $597,000
  • Tax Rate: 1.2%
  • Annual Tax: $7,164
  • Monthly Escrow: $597

Example 3: $1,000,000 Home

  • Assessed Value: $1,000,000
  • Homestead Tax Credit Applied: -$3,000 (estimated)
  • Net Taxable Value: $997,000
  • Tax Rate: 1.2%
  • Annual Tax: $11,964
  • Monthly Escrow: $997

Note: Tax credits shown are estimates and REQUIRE APPLICATION by specified deadlines. Actual rates vary by tax district within the county. Credits reduce your tax bill, not your assessed value.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Sioux County require property tax escrow accounts to ensure timely payment of property taxes. Your monthly mortgage payment includes a portion that goes into this escrow account, which the lender uses to pay your annual property tax bill when due. Lenders typically collect 1/12th of your annual tax bill each month, plus an additional cushion amount as allowed by federal regulations.

Property tax payments in North Dakota are typically due in two installments, though specific due dates vary by county. Your lender will receive tax bills directly from the county and pay them on your behalf. You should receive an annual escrow statement showing all deposits and payments made from your account. If your property taxes increase significantly (as with the current 23.2% increase), your lender may require an escrow shortage payment or increase your monthly payment to cover the higher taxes. Always verify that your lender has paid your taxes by checking with the county treasurer, as you remain ultimately responsible for payment even when using escrow.

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 Sioux County for 2025? A: Property tax due dates vary by county in North Dakota. Contact the Sioux County Treasurer for specific 2025 payment deadlines and installment options.

Q: What tax credits are available and how do I apply? A: North Dakota offers a Homestead Property Tax Credit for qualifying homeowners. Applications for homestead and military tax credits are due by July 1st. These credits reduce your tax bill and require annual application - they are NOT automatic.

Q: How does the Homestead Tax Credit work? A: The Homestead Credit typically caps assessment increases rather than reducing market value. It limits how much your assessed value can increase year-over-year (often to 10%), providing tax relief for long-term homeowners. You must file an application to receive this credit.

Q: When can I appeal my property assessment? A: The assessment protest filing period in Sioux County runs from October 9 to October 30. You must file your appeal during this window to contest your property's assessed value.

Q: What happens if I pay my property taxes late? A: Late payments typically incur penalties and interest charges. Contact the Sioux County Treasurer for current penalty rates and payment options if you cannot meet the deadline.

Q: Can I pay my property taxes online? A: Many North Dakota counties offer online payment options. Check the Sioux County Treasurer's website or contact their office directly for available electronic payment methods.

Q: Why did my taxes increase 23.2% this year? A: Sioux County's tax rates increased 23.2% for the 2025 levy year due to local government budget decisions. This increase affects all property owners in the county, though individual impacts vary by property value and applicable tax credits.

Q: Do I qualify for property tax exemptions as a senior citizen? A: North Dakota offers a Property Tax Homestead Exemption for residents 70 and older who meet certain income requirements. This program delays payment of property taxes until the property is sold. Contact your county assessor to determine eligibility and application requirements.

Q: How do special taxing districts affect my bill? A: Your property may be located in multiple taxing districts (school, fire, water, etc.), each with separate mill levies. This is why tax rates vary significantly by location within Sioux County. Your tax statement will show all applicable district taxes.

Q: What if I disagree with supplemental taxes? A: Supplemental tax assessments can be appealed through the same process as annual assessments, but timing may differ. Contact the county assessor immediately if you believe a supplemental assessment is incorrect.

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