Complyt

Complyt is an API-led transaction tax engine for businesses that need tax calculation connected to customer records, nexus rules and exemptions. It suits SaaS, e-commerce, retail and professional-services companies building tax into their own systems or Xero invoicing. The main appeal is contextual transaction handling; the main constraint is that rate lookup and Xero calculations require U.S. addresses, while pricing is custom.

Overview

Complyt calculates sales tax on transactions and returns both the tax amount and applicable rate. Its workflow covers creating customers and transactions through the API, recording line items, shipping addresses and transaction status, then retrieving either a concise result or expanded item, tax-rate and jurisdictional-rule data. That makes it a stronger fit for an integrated tax process than for teams seeking only a simple public rate table.

The documentation also describes VAT and global-tax support for international transactions, while the dedicated U.S. sales-tax rates endpoint currently accepts U.S. addresses only. The product recognizes retail, reseller and marketplace customer types, which can change nexus thresholds and taxability.

Key features

Transaction and nexus logic

Complyt separates estimates from invoices when monitoring nexus: estimates do not count toward thresholds, while invoices do. This distinction is useful for businesses that quote or forecast before billing, because exploratory activity does not inflate their threshold calculations. Nexus monitoring, marketplace support and exemption-certificate management are built into the model rather than treated as separate lookups.

Exemptions and address quality

Exempt customers can be managed through an exemptions endpoint. The Address Validation API checks U.S. addresses against official postal databases and returns suggested matches with confidence scores, giving integrations a way to catch address problems before tax is calculated. These tools are valuable where jurisdiction and exemption accuracy matter, but they are centered on U.S. address data.

Xero integration

The Xero integration calculates line-level U.S. sales tax using jurisdiction, nexus, exemptions and product type. It calculates tax only when a Xero invoice has a U.S. shipping or billing address, and Complyt recommends complete addresses. Companies with international or incomplete invoice addresses will need another process for those transactions.

API access

Authentication uses a client ID and client secret to obtain an Auth0 bearer token. Tokens expire after 24 hours, so an implementation must handle renewal. That is a conventional server-to-server pattern, but it makes ongoing integration work essential rather than optional.

Pricing

Complyt uses paid, custom pricing. The company provides pricing on request rather than published plans, so it is better suited to organizations willing to scope an API deployment with the vendor than to buyers comparing predictable self-serve tiers. There is no stated free plan, seat allowance, transaction quota or trial term to use for a lower-risk evaluation.

Platforms

Complyt is available through an API and on the web. The API is the core route for customer, transaction, authentication and tax-retrieval workflows; the web presence does not replace that integration requirement.

Who it's for

Choose Complyt when your SaaS, e-commerce, retail or professional-services business needs transaction tax calculations tied to nexus monitoring, customer categories, exemptions or marketplace activity. It is particularly suitable for teams already able to maintain an API integration and for Xero users whose invoices consistently carry complete U.S. addresses.

Look elsewhere if you need transparent self-service pricing, a broad address-based rate lookup outside the United States, or a tax workflow that does not depend on engineering work. International VAT support is described, but the documented rate endpoint and Xero calculation path remain U.S.-focused.

Pros and cons

Pros

• Context-aware calculations: Tax results can incorporate customer type, nexus status, exemptions, product type and jurisdiction.
• Useful transaction records: Line items, shipping addresses and status support auditable application workflows, with expanded responses for detailed analysis.
• Practical compliance controls: Nexus monitoring, exemption management, marketplace support and address validation cover common operational risks.
• Xero line-level tax: Eligible U.S. invoices can receive detailed tax calculations rather than a single invoice-wide figure.

Cons

• Custom pricing: Buyers cannot estimate cost from published plan prices, quotas or seat terms.
• U.S.-bound address workflows: The rates endpoint and Xero calculation require U.S. addresses, limiting their usefulness for non-U.S. billing.
• Integration overhead: Bearer-token authentication, 24-hour token expiry and API-created records require technical ownership.

Alternatives

Yonda Tax is a better starting point for teams wanting a free nexus-monitoring plan and worldwide tax-liability calculations, with paid U.S. sales-tax options available separately.

ShipVAT suits buyers seeking a free API tier with 100 calls per month, tax calculation and supported-jurisdiction coverage.

Zamp is worth considering for teams that want a free 30-day sandbox before moving to a U.S. compliance offering.

Kintsugi fits organizations prioritizing free global physical and economic nexus monitoring, exposure auditing and risk assessment.

CCH SureTax offers technology-only, filing-and-remittance, and fully outsourced plan structures for buyers seeking broader compliance-service choices.

Sovos Sales & Use Tax targets growing organizations with straightforward requirements and broad geographic footprints, including e-commerce retailers and smaller businesses.

Taxolio is the clearer option for web-based managed compliance with a published $99 per month price for two states.

Taxually is an alternative for buyers purchasing discrete tax-authority payments or yearly reporting services.

For category comparisons, browse Sales Tax Software and Tax Engine Software.

Verdict

Complyt is a strong choice for an engineering-backed business that needs transaction tax decisions tied to nexus, exemptions, customer type and marketplace context, especially when using Xero with complete U.S. addresses. Its custom pricing, U.S.-centered address requirements and ongoing API maintenance are the reasons to choose a more transparent, broader or more self-service alternative.