OpenSalesTax
OpenSalesTax: A focused, free engine for developers who need self-managed U.S. sales-tax calculations. Ranked #25 of 28 in Tax Engine Software by our editors (6.9/10); pricing: Free plan; best for self-hosted U.S. sales-tax developers.
At a glance
- Editor score6.9 / 10
- PricingFree plan
- Best forSelf-hosted U.S. sales-tax developers
- Free planYes
- Paid fromFree
- Facts checked22 Sep 2026
Where it wins
- Free and open source with self-hosted deployment
- Line-item calculations with jurisdiction-level breakdowns
- REST API, PostgreSQL dumps, and Docker Compose support
Where it doesn't
- Covers sales tax rather than broader tax types
- Calculation only; no filing or remittance
- Docs are the listed support channel
Our verdict on OpenSalesTax
OpenSalesTax is an open-source API for calculating destination-based U.S. sales tax. It is designed for developers, merchants, and businesses that want a free, self-managed calculation engine rather than a filing or remittance service. The product supports transaction line-item calculations, ZIP-code rate lookups, jurisdiction-level breakdowns, taxability matrices, and state-specific rules. Its coverage includes U.S. states, the District of Columbia, and Puerto Rico.
The deployment model is central to OpenSalesTax. It can run through Docker Compose, PostgreSQL data dumps, or source installation, with a REST API documented through OpenAPI. Live demo and API instances provide an accessible way to review the service interface. This approach suits solo developers and small to mid-market teams that can manage their own infrastructure and want control over their tax calculation environment. The published product details describe a free offering, with no paid tiers adding separate capabilities.
OpenSalesTax stays focused on sales-tax calculation. It does not provide tax filing, remittance, legal advice, or address validation, so businesses needing a broader compliance workflow should choose a platform that includes those services. The self-hosted model also places deployment and operational responsibility with the adopting team, while documentation is the listed support channel. Choose OpenSalesTax when a free, open-source API and self-managed U.S. sales-tax calculations meet the requirement; look elsewhere when integrations, managed operations, broader tax types, or end-to-end compliance services are priorities.
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OpenSalesTax pricing
OpenSalesTax fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Tax jurisdictions | Not verified |
| Transaction limit | Not verified |
| Real-time calculation | Not verified |
| Tax types | Sales_tax |
| API access | Yes |
| Commerce connectors | Not verified |
| Exemption certificates | Not verified |
| Deployment | Self-hosted |
| Support | Docs |
| Built for | Solo, Small business, Mid-market (editorial estimate) |
| Pricing | Free plan |
| Website | github.com |
| Facts checked | 22 Sep 2026 |
Alternatives to OpenSalesTax
- Avalara AvaTaxA broad tax engine for high-volume, multi-tax compliance workflows.9.4
- ONESOURCE DeterminationA high-capacity global tax engine with broad coverage and contact-sales pricing.9.3
- Vertex Cloud Indirect TaxA broad enterprise tax engine for complex, multi-jurisdiction indirect tax operations.9.1
See all OpenSalesTax alternatives →
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OpenSalesTax is listed in our Tax Engine Software directory. Add the badge to your site — it links back to this page.
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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