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Updated 2025 Tax Year

Plymouth County
Property Tax Guide

Everything you need to know about property taxes in Plymouth County, IA. 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
Base rate ~1% plus local levies, varies significantly by school district and city
1st Due
Sep 30
2nd Due
Mar 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Plymouth County, Iowa operates on a property tax system that funds essential local services including schools, county government, cities, townships, and special districts. Property taxes are the primary funding source for public education, road maintenance, emergency services, and other community infrastructure. The county follows Iowa's property tax structure with an approximate base rate of 1%, though actual rates vary significantly based on your specific location within the county due to overlapping special taxing districts such as school districts, city levies, and other local authorities.

Property owners in Plymouth County receive their annual property tax statement in August from the County Treasurer, with taxes paid in two installments due in September and March. The total effective tax rate for any property depends on the combination of county, city, school district, and other special district levies that apply to that specific parcel. With proposed increases in property values for 2025, property owners should expect potential changes in their tax obligations even if levy rates remain constant.

Section 2

What Makes Up Your Tax Bill

ComponentRate RangeDescription
County General FundVariesBasic county services, roads, administration
School District LevyVaries by DistrictK-12 education funding, varies significantly by school district
City LevyVaries by MunicipalityMunicipal services (applies only to properties within city limits)
Township LevyVaries by TownshipRural services for unincorporated areas
Special DistrictsVariesDrainage districts, fire protection, library districts

Note: Specific rates for the current fiscal year are determined annually and vary by location within Plymouth County. The 2025 property tax rates are not yet finalized, with proposed increases in property values suggesting potential changes. Property owners should refer to their individual tax statements for exact rates applicable to their parcel, as rates can vary significantly between different areas of the county depending on which combination of taxing authorities serve that location.

Section 3

When Are Property Taxes Due?

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

First Installment
Sep 30
Delinquent after Dec 10
Second Installment
Mar 31
Delinquent after Apr 10
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 property taxes in Plymouth County are additional tax assessments that occur when there are changes to property ownership, new construction, or improvements made to existing properties during the tax year. These supplemental taxes are calculated based on the difference between the previous assessment and the new assessed value, prorated for the portion of the tax year remaining after the change occurred.

Common triggers for supplemental taxes include the completion of new construction projects, major home improvements or additions, subdivision of property, or changes in property use classification. For example, if you complete a $100,000 home addition in January, you would receive a supplemental tax bill covering the additional tax liability for the remaining months of that tax year based on the increased assessed value from the improvement.

Example Calculation

$300,000 Home Example:

  • Market Value: $300,000
  • Assessed Value (100%): $300,000
  • Less: Homestead Credit (if applied): varies
  • Net Taxable Value: ~$300,000
  • Annual Tax (estimated 1.5% effective rate): $4,500
  • Monthly Escrow: ~$375

$600,000 Home Example:

  • Market Value: $600,000
  • Assessed Value (100%): $600,000
  • Less: Homestead Credit (if applied): varies
  • Net Taxable Value: ~$600,000
  • Annual Tax (estimated 1.5% effective rate): $9,000
  • Monthly Escrow: ~$750

$1,000,000 Home Example:

  • Market Value: $1,000,000
  • Assessed Value (100%): $1,000,000
  • Less: Homestead Credit (if applied): varies
  • Net Taxable Value: ~$1,000,000
  • Annual Tax (estimated 1.5% effective rate): $15,000
  • Monthly Escrow: ~$1,250

Note: These examples use estimated rates. Actual rates vary by specific location within Plymouth County. Tax credits such as Homestead Credit require annual application and are not automatic.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Plymouth County require property tax escrow accounts, where monthly tax payments are collected along with your mortgage payment and held until tax due dates. Since Plymouth County property taxes are due twice yearly in September and March, your lender will typically collect 1/12th of your annual tax bill each month and pay the County Treasurer directly when taxes are due.

Property owners should verify that their mortgage company has current tax information, especially after reassessments or when tax credits are applied or removed. You can monitor your escrow account through your mortgage servicer and should receive an annual escrow analysis showing projected taxes for the coming year. If you pay taxes directly (without escrow), remember that payments are due to the Plymouth County Treasurer by the September and March deadlines to avoid penalties and potential tax sale procedures.

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 Plymouth County? A: Property taxes are due twice yearly - in September and March. Current tax year payments must be made by the March deadline to avoid tax sale procedures.

Q: What tax credits are available and how do I apply? A: Homestead Credit and Military Exemption are available through the County Assessor's office. These require annual application and are not automatic - you must apply with the Assessor to receive these credits.

Q: How does the Homestead Credit work? A: The Homestead Credit limits annual assessment increases rather than reducing market value. It must be applied for annually with the County Assessor and helps control property tax growth on your primary residence.

Q: When are properties reassessed in Plymouth County? A: Iowa properties are assessed annually. Assessment notices are typically sent in the spring, with appeal deadlines shortly thereafter. Contact the County Assessor's office for specific assessment dates and appeal procedures.

Q: What happens if I pay my property taxes late? A: Late payments incur penalties and interest. Properties with delinquent taxes may be subject to tax sale procedures, so timely payment by the March deadline is crucial.

Q: Can I pay my property taxes online? A: Contact the Plymouth County Treasurer's office for available online payment options and accepted payment methods for property tax payments.

Q: Why did my taxes increase if rates didn't change? A: Property tax bills can increase due to rising assessed values, new special district levies, or loss of previously applied tax credits. With proposed 10% property value increases for 2025, many owners may see higher tax bills.

Q: How do special taxing districts affect my tax bill? A: Your total tax rate includes county, school district, city (if applicable), township, and any special district levies. Rates vary significantly across different areas of Plymouth County based on which taxing authorities serve your specific location.

Verified Sources

Backed by 10 Official Government Sources

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

01
Local Government Property Valuation Systemplymouthcountyiowa.gov
02
County
April 1, 2025.docx - Plymouth County Iowaco.plymouth.ia.us
03
$34.29legis.iowa.gov
04
Tax Doc
How Do I Pay Property Taxes?iowa.gov
05
Assessorplymouthcountyiowa.gov
06
County
Special Election - Plymouth County Iowaco.plymouth.ia.us
07
County
I want to - Plymouth County Iowaplymouthcountyiowa.gov
08
Auditorplymouthcountyiowa.gov
09
2021 Minutesplymouthcountyiowa.gov
10
County
COUNTY BUDGET INSTRUCTIONS Fiscal Year 2017/2018iowaonline.state.ia.us
All sources verified as of 2025 Tax Year

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