Sales tax in St. Mary Parish, Louisiana
There is no single sales tax rate in St. Mary Parish. It runs from 9.45% to 10.45% depending on the exact address, because cities and special districts inside the county levy their own on top of the 5% state rate. The 5% state rate applies everywhere in the county; everything above that depends on where you are standing. These rates were read from Louisiana's own published schedule and checked on September 9, 2026.
What is the sales tax rate in St. Mary Parish?
| Louisiana state rate | 5% |
|---|---|
| Local tax applying countywide | 3.15% |
| Lowest combined rate in the county | 9.45% |
| Highest combined rate in the county | 10.45% |
The combined figures are the lowest and highest totals anywhere in St. Mary Parish, so the rows above do not add up to them.
How much sales tax is that on a purchase in St. Mary Parish?
At 9.45%, a $100 purchase carries $9.45 in sales tax and a $1,000 purchase $94.50, at the lowest rate in the county. At the highest, 10.45%, the same purchases carry $10.45 and $104.50. That is general merchandise; Louisiana taxes some categories, often groceries, differently, as the note below explains.
Among Louisiana's 63 counties, St. Mary Parish's lowest rate ranks 30th highest. See every Louisiana county.
Sales tax in counties next to St. Mary Parish
St. Mary Parish borders 4 counties. The lowest rate next door is 8.5% in St. Martin Parish, LA, which is $9.50 less on a $1,000 purchase than the lowest rate in St. Mary Parish.
| County | Combined sales tax |
|---|---|
| Terrebonne Parish, LA | 10.5% |
| Assumption Parish, LA | 10% to 10.5% |
| St. Mary Parish, LA (this county) | 9.45% to 10.45% |
| Iberia Parish, LA | 9.25% to 11.25% |
| St. Martin Parish, LA | 8.5% to 11% |
Why the rate here is not the whole story
Louisiana charges 5 percent statewide, and every local sales tax is levied and collected locally rather than by the state, by the parish school board, the parish governing authority, the sheriff's law enforcement district, municipalities and economic development districts, so the parish line is not the tax boundary. 3.15 percent applies everywhere in the parish, levied by the school board at 1.9 percent, a solid waste levy at 0.75 percent and the law enforcement district at 0.5 percent. No one rate covers the whole parish: the floor of 9.45 percent is at Berwick and the ceiling of 10.45 percent is at Franklin.
How do I find the exact rate for an address in St. Mary Parish?
Use Louisiana's own address lookup. In St. Mary Parish the rate depends on the address, anywhere from 9.45% to 10.45%.
Who has to collect sales tax in St. Mary Parish?
Any seller with a physical presence in Louisiana collects at the rate for the address of the sale; a remote seller does once it passes Louisiana's economic nexus threshold. Louisiana sales tax covers the statewide rules and what is exempt.
Work out your own numbers
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Sales tax calculator
Tax on a specific purchase at this county's rate, and the total you will actually pay.
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Do you have to collect?
Whether your sales into Louisiana cross its economic nexus threshold. A different question from the rate.
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Property tax in St. Mary Parish
The other local tax: effective rate and median bill for this county.
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Sales tax by county
Every US county, and how Louisiana compares with the rest of the country.
Sources
- St. Mary Parish rates: Louisiana Association of Tax Administrators, St. Mary Parish sales and use tax rate table, edition effective April 1 2025, https://lataonline.org/for-taxpayers/city-to-parish-index/st-mary/; state rate from Louisiana Department of Revenue, Tax Reform Frequently Asked Questions, General Sales Tax (edition dated September 23 2025), https://dam.ldr.la.gov/miscellaneous/Sales%20Tax%20Reform%20FAQs%209.23.25.pdf
- Collected and verified September 9, 2026. Confidence: P on the rate components, P on the range (P read on a primary agency page, S strong but indirect, U unverified).