Dorchester County Tax Map: TMS Search, GIS Viewer, and Copies

The Dorchester County tax map is the county’s official record of every land parcel within its borders, each tagged with a Tax Map Sequence (TMS) number that ties the property to its assessment, deed history, and tax bill. You can view it two ways: online through the county’s GIS portal, or as a physical copy ordered from the Assessor’s office.¹

The TMS Number and Why It Matters

Every parcel in the county carries a unique TMS number. The Assessor’s office, the Register of Deeds, and the tax billing system all use the same number to pull records on the same piece of land, so it appears on closing documents, mortgage paperwork, and tax bills.²

The map also shows calculated acreage and boundary lines, and it links out to recorded documents held by the Register of Deeds. Deeds, mortgages, and plats are archived there and referenced by book and page number.³

How to Search for a Parcel

The fastest search uses the TMS number itself. Look on your most recent tax bill, your closing statement, or your mortgage documents. When you enter the TMS number into the county’s online lookup, drop all dashes and decimals.²

No TMS number? The search tools also accept a street address or the property owner’s name as it appears on the tax roll. Spelling has to be exact. A slight mismatch in the owner’s name or a missing apartment number will return no results. Searching by owner works best if you put the last name first and keep it short, which absorbs minor recording variations.

Using the Online GIS Viewer

Dorchester County hosts a GIS viewer accessible through its Maps/GIS page, and you can use it from any browser without visiting the Assessor’s office.¹

Type an address or TMS number into the search bar and the map centers on the parcel with its boundaries highlighted. A side panel controls the layers. You can turn on aerial photography to see the actual land, overlay topographic contours for elevation, or place parcel lines over satellite imagery. Zoom in with the mouse wheel and individual lot lines come into view. Clicking a parcel opens a summary of its assessment details.

The toolbar also includes measurement tools for distances between boundary points and rough area calculations for shapes you draw on the screen. These are useful when checking the map against a survey or deed description, but they are approximations, not survey-grade measurements.

Checking Flood Zones

One practical use of the mapping tools is confirming whether a parcel sits inside a FEMA flood zone. The county links directly to an Interactive Flood Insurance Rate Map built on FEMA’s ArcGIS platform, which shows Special Flood Hazard Areas that trigger mandatory flood insurance for federally backed mortgages. The link lives on the county’s Flood Zones page under Emergency Management.⁴

For questions about a specific parcel’s flood designation, the Building Services Department has a Floodplain Manager who can explain how a classification affects permits and insurance.

Ordering Physical or Certified Copies

The GIS page includes a Map Request Form for printed reproductions. Custom mapping and research services are also available, with fees that vary by the size and complexity of the request. To purchase core GIS data files, you’ll need to complete a Limited Use Agreement and a Data Order Form.⁵

For closings or legal proceedings that need certified documents, call the Assessor’s office to confirm what format they can produce and whether certification is available for your purpose.

From Map Data to Tax Bill

The tax map identifies the parcel; the assessment ratio determines what share of its market value gets taxed. South Carolina does not tax property at full market value. Each class of property is taxed on a different percentage.

Owner-occupied primary homes and up to five contiguous acres: 4% of fair market value.
Other residential and commercial property, including rentals, second homes, vacant land, and commercial real estate: 6%.
Manufacturing and utility property: 10.5%.
Qualifying agricultural and timber land owned by individuals or small partnerships: 4% of agricultural use value, not development value.

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That assessed value is then multiplied by local millage rates. For 2025, Dorchester County’s combined county millage rate is 79.4 mills (0.0794), but your total millage also folds in school district, municipal, fire district, and other levies that vary by location within the county.⁷

The 4% rate on a primary home isn’t automatic. You have to apply through the Assessor’s office. Without that application, the county defaults to 6%, which puts a 50% higher assessed value on the same home. Once you have the 4% classification, you keep it without reapplying unless you move or change how the property is used.⁶

Agricultural classification appears on the tax map and in the GIS record, so you can check whether a parcel you’re considering already carries agricultural status. If land is later taken out of agricultural use, the county can impose roll-back taxes covering the difference between the agricultural and standard rates for prior years.

Reassessment Cycles

South Carolina law requires every county to reassess property values on a five-year cycle.⁸ During a reassessment year, the Assessor’s office reviews market data and adjusts the fair market value of each parcel to reflect current conditions. You’ll receive a reassessment notice in the mail. Between reassessment years, your value generally stays the same unless you make improvements or the property changes hands.

Fixing a Wrong Value, Boundary, or Acreage

If a reassessment notice shows a value that looks too high, or the tax map has the wrong acreage or boundaries, you can file an appeal with the Assessor. In a reassessment year, you have 90 days from the mailing date of the assessment notice to submit a written objection. You can challenge the fair market value, the special use value, the assessment ratio, or the overall tax assessment.⁹

In years without a reassessment notice, you can still appeal in writing at any time. An appeal submitted before the first penalty date applies to the current tax year; one submitted after applies to the following year.⁹

The Assessor’s valuation is presumed correct unless you prove otherwise. Saying the number feels wrong isn’t enough. The strongest evidence is a recent independent appraisal from a licensed appraiser, comparable sales data for similar properties nearby, or documentation of physical problems that reduce value. If you hire an appraiser, that person’s testimony serves as your primary evidence at the hearing. Argument from an attorney alone doesn’t carry evidentiary weight.

For boundary or acreage errors on the tax map itself, you’ll usually need a professional land survey to show the discrepancy. Bring the survey to the Assessor’s office along with the supporting deed descriptions. A corrected map can also change your assessed value if the actual acreage differs from what the county has on record.

Contacting the Assessor’s Office

The Dorchester County Assessor’s office handles questions about property values, tax map corrections, assessment ratios, and applications for the 4% legal residence classification.¹⁰

Phone: (843) 832-0162 or (843) 563-0162
Address: 201 Johnston St., St. George, SC 29477
Hours: Monday through Friday, 8:30 a.m. to 5:00 p.m., closed on holidays

For flood zone questions, contact the Floodplain Manager in the Building Services Department. For recorded deeds and plats, the Register of Deeds maintains a public research library of all land transfer documents filed in Dorchester County.³

1
Dorchester County. GIS Property Search
2
Dorchester County. CAMA Property Lookup
3
Dorchester County. Register of Deeds
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Dorchester County. Flood Zones
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Dorchester County. GIS Data Layers
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South Carolina Legislature. South Carolina Code Title 12 Chapter 43 – Section 12-43-220
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South Carolina Association of Counties. Property Tax Rates by County 2025
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Dorchester County. Reassessment Information
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South Carolina Legislature. South Carolina Code 12-60-2510 – Property Tax Assessment Procedures
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Dorchester County. Assessor