# Avalara Developer — Full Documentation Corpus > A flattened, plain-text documentation corpus for developer.avalara.com, intended for AI agents that need the substance of the docs (concepts, workflows, authentication, endpoints, and product detail) in a single fetch without rendering JavaScript. For a lightweight link-only index, see https://developer.avalara.com/llms.txt > Generation note: This file is the canonical end-state structure for llms-full.txt. In production it should be generated automatically from the live documentation pages (each section sourced from the page named in its `Source:` line) and regenerated on every docs build so it never drifts from the source of truth. --- # About Avalara Developer Source: https://developer.avalara.com/ Avalara provides cloud-based tax compliance solutions. The developer site (developer.avalara.com) is the central hub for developers integrating Avalara products into their applications. It covers REST and GraphQL APIs, unified SDKs, MCP (Model Context Protocol) servers for AI agents, interactive API playgrounds, and integration guides. Coverage spans sales and use tax, excise tax, communications tax, VAT, cross-border duties, e-invoicing and live reporting, exemption certificate management, managed returns, business licensing and registrations, 1099 & W-9, and lodging tax. --- # Choosing the Right API Source: https://developer.avalara.com/products/avatax/api.md AvaTax REST v2 is the primary API for sales and use tax calculation. Use REST v2 for most sales/use tax integrations unless a different product API is specifically required. - The legacy SOAP API and REST v1 are superseded. New integrations should use REST v2; existing integrations should migrate using the refactor guides. - SOAP to REST v2: https://developer.avalara.com/soap-to-restv2-refactor-guide/ - REST v1 to REST v2: https://developer.avalara.com/restv1-to-restv2-refactor-guide/ - Communications tax uses AvaTax for Communications — a separate API with different endpoints and a different data model. Do not mix Communications calls with AvaTax REST v2. - Managed Returns is a GraphQL API, not REST. Do not confuse it with the AvaTax REST API. - EU/UK VAT uses AvaTax for VAT (the REST v2 API configured for VAT). - Cross-border duties use the AvaTax Cross-Border API. - E-invoicing mandates use the Avalara E-Invoicing and Live Reporting API. What Avalara does NOT do: Avalara is a tax compliance platform, not accounting, ERP, or payment processing software. It integrates with those systems rather than replacing them. --- # Authentication Source: https://developer.avalara.com/ Avalara APIs use HTTP Basic Authentication with account credentials (account ID and license key) or Bearer tokens. Store credentials securely and never hardcode them in source or commit them to version control. - Connectivity/auth check: `GET /api/v2/utilities/ping` - Sandbox base URL: `https://sandbox-rest.avatax.com` - Portal OAuth API (token exchange and external integration): https://developer.avalara.com/api-reference/oauth/oauth/ --- # Sandbox vs Production Source: https://developer.avalara.com/freeTrial.md Avalara provides a free sandbox environment for testing. Start in the sandbox before moving to production. - Sandbox sign-up: https://developer.avalara.com/freeTrial.md - Use the sandbox base URL (`https://sandbox-rest.avatax.com`) with sandbox credentials. - Production uses production credentials and the production base URL. Validate end-to-end behavior in sandbox first, then switch credentials and base URL for production cutover. --- # Key Concepts Source: https://developer.avalara.com/ - Tax Calculation: Determined by geolocation, product type, and jurisdiction rules. AvaTax handles this automatically given valid addresses and tax codes. - Nexus: A tax obligation threshold that determines where a business must collect and remit tax. Configure nexus in the AvaTax account before calculating tax. - Transaction: A taxable event (sale, refund, transfer) submitted to AvaTax. Transactions can be saved, committed, voided, or adjusted. - Tax Jurisdiction: The region (state, county, city, district) whose tax rules apply to a transaction. AvaTax resolves jurisdictions automatically from addresses. - Tax Code: A product classification code (e.g., `P0000000` for tangible personal property) that determines taxability rules. Use Avalara-defined tax codes — do not guess. Refer to the AvaTax tax code search or the product tax categories documentation: https://developer.avalara.com/products/avatax/api.md - Exemption Certificate: Documentation that allows a transaction to be tax-exempt. Managed via ECM APIs and associated with a customer entity in AvaTax. --- # Key Workflows Source: https://developer.avalara.com/ ## Standard Tax Calculation 1. Validate address → `ResolveAddress` (`POST /api/v2/addresses/resolve`) 2. Create transaction with line items, addresses, and tax codes → `CreateTransaction` (`POST /api/v2/transactions/create`) 3. AvaTax returns calculated tax amounts per jurisdiction 4. Commit the transaction when the sale is finalized → `CommitTransaction` 5. Adjust or void if needed → `AdjustTransaction` / `VoidTransaction` ## Compliance (Returns) Workflow 1. Calculate and commit transactions via AvaTax REST v2 2. Transactions flow into Managed Returns automatically 3. File returns and manage remittance via the Managed Returns API (GraphQL): https://developer.avalara.com/products/returns/api/ 4. Monitor notices and filing status ## Global Tax Workflow - US sales tax: AvaTax REST v2 - EU/UK VAT: AvaTax for VAT (REST v2 configured for VAT) - Cross-border duties: AvaTax Cross-Border API - E-invoicing mandates: Avalara E-Invoicing API ## Exemption Certificate Workflow 1. Create customer → `CreateCustomers` (`POST /api/v2/companies/{id}/customers`) 2. Link certificate to customer → `CreateCertificates` (`POST /api/v2/companies/{id}/certificates`) 3. AvaTax applies the exemption automatically when the customer transacts For existing CertCapture customers, the CertCapture API v2 applies; new integrations should use the AvaTax REST v2 Certificates endpoints. --- # Key AvaTax REST v2 Endpoints Source: https://developer.avalara.com/products/avatax/api.md - `GET /api/v2/utilities/ping` — Connectivity and authentication check - `POST /api/v2/transactions/create` — Calculate tax (create transaction) - `POST /api/v2/addresses/resolve` — Validate and geocode an address - `POST /api/v2/transactions/{code}/commit` — Finalize a transaction - `POST /api/v2/transactions/{code}/void` — Cancel a transaction - `POST /api/v2/transactions/{code}/adjust` — Modify a committed transaction - `GET /api/v2/transactions/{code}/audit` — Retrieve audit data for a transaction - `POST /api/v2/transactions/{code}/refund` — Process a refund transaction - `POST /api/v2/companies/{id}/customers` — Create customer records for exemption management - `POST /api/v2/companies/{id}/certificates` — Create and link exemption certificates Full endpoint reference: https://developer.avalara.com/products/avatax/api.md --- # Products Source: https://developer.avalara.com/ - AvaTax (https://developer.avalara.com/products/avatax.md): Calculate and apply sales tax in real time using up-to-date rates and rules across jurisdictions. - AvaTax for Communications (https://developer.avalara.com/products/communications.md): Communications taxes using telecom-specific rules, rates, and regulatory logic. Separate endpoints and data model from AvaTax REST v2. - AvaTax for Excise (https://developer.avalara.com/products/excise.md): Excise taxes using product-specific rules and regulatory requirements. - AvaTax Cross-Border (https://developer.avalara.com/products/crossborder.md): Duties, taxes, and import fees for cross-border transactions and landed cost estimation. - AvaTax Brazil (https://developer.avalara.com/products/avatax-brazil.md): Brazil taxes using localized rules, rates, and compliance logic. - Tariff Code Classification (https://developer.avalara.com/products/item-classification.md): Assign products to correct HS or tariff codes for duty calculation and trade compliance. - Avalara Tax Content (https://developer.avalara.com/products/avalara-tax-content.md): Up-to-date tax rates, rules, and jurisdiction mappings for ERP, POS, and billing systems. - Avalara Managed Returns API (https://developer.avalara.com/products/returns.md): Embed tax return preparation, filing, and remittance. GraphQL. - Avalara Returns Excise (https://developer.avalara.com/products/excisereturns.md): Automate excise tax return preparation, filing, and reporting. - Exemption Certificate Management (https://developer.avalara.com/products/ecm.md): Collect, validate, and manage exemption certificates for audit-ready compliance. - Avalara E-Invoicing and Live Reporting (https://developer.avalara.com/products/e-invoicing.md): Automate electronic invoicing and real-time reporting for global mandates. - Tax Registrations and Business Licenses (https://developer.avalara.com/products/registration-and-licensing.md): Register for tax accounts across jurisdictions. - Avalara 1099 & W-9 (https://developer.avalara.com/products/avalara-1099-and-w9.md): Collect, validate, and report vendor tax forms for IRS compliance. - MyLodgeTax (https://developer.avalara.com/products/mylodge.md): Calculate, file, and manage lodging taxes for short-term rentals. - AvaTax for VAT (https://developer.avalara.com/products/vat-calculation.md): VAT using country-specific rules, rates, and compliance logic. - VAT Reporting (https://developer.avalara.com/products/vat-reporting.md): Prepare and submit VAT reports using aggregated transaction data. GraphQL. --- # API Reference Source: https://developer.avalara.com/api-reference/ Avalara provides REST and GraphQL APIs. The AvaTax REST v2 API is the primary integration point for tax calculation. Each API page includes interactive documentation with endpoint details, request/response schemas, and code samples. - AvaTax REST API v2: https://developer.avalara.com/products/avatax/api.md - Communications Tax API v2: https://developer.avalara.com/products/communications/api.md - Excise Tax API v1: https://developer.avalara.com/products/excise/api.md - Tariff Code Classification API: https://developer.avalara.com/products/item-classification/api.md - Item Classification API: https://developer.avalara.com/products/item-classification/api.md - Self-Serve Tariff Classification API: https://developer.avalara.com/products/self-serve-tariff-code/api.md - AvaTax Brazil API: https://developer.avalara.com/products/avatax-brazil/api.md - Avalara Tax Content API: https://developer.avalara.com/products/avalara-tax-content/api.md - E-Invoicing API: https://developer.avalara.com/products/e-invoicing/api.md - Activation Service API: https://developer.avalara.com/products/activation-service/api.md - Exemption Certificate Management API: https://developer.avalara.com/products/ecm/api.md - Managed Returns API (GraphQL): https://developer.avalara.com/products/returns/api/ - VAT Reporting API (GraphQL): https://developer.avalara.com/products/vat-reporting/api/ - MyLodgeTax API: https://developer.avalara.com/products/mylodge/api.md - Avalara 1099 & W-9 API: https://developer.avalara.com/products/avalara-1099-and-w9/api.md - Portal OAuth API: https://developer.avalara.com/api-reference/oauth/oauth/ - Business API: https://developer.avalara.com/api-reference/business/v1/ - Shared Services API: https://developer.avalara.com/products/shared-services/api.md - Registration and Licensing APIs: https://developer.avalara.com/products/registration-and-licensing/api.md --- # SDKs Source: https://developer.avalara.com/sdk/ Avalara publishes unified SDKs for its APIs (AvaTax, Communications, 1099 & W-9, E-Invoicing). These SDKs wrap the REST API and provide typed models, authentication helpers, and retry logic. Always check the package registry for the latest version before installing (for example, `npm view avalara-sdk version`) rather than pinning a version from memory. - AvaTax SDK (C#, Java, PHP, Ruby, TypeScript, Python): https://developer.avalara.com/products/avatax/sdk.md - Communications SDK: https://developer.avalara.com/products/communications/sdk.md - Avalara 1099 & W-9 SDK: https://developer.avalara.com/products/avalara-1099-and-w9/sdk.md - E-Invoicing SDK: https://developer.avalara.com/products/e-invoicing/sdk.md --- # MCP Servers Source: https://developer.avalara.com/mcp-servers.md Avalara provides Model Context Protocol (MCP) servers that let AI agents and LLM-powered tools interact with Avalara APIs. Each server exposes tools for a specific product area. - AvaTax MCP Server: https://developer.avalara.com/products/avatax/mcp.md — tax calculation and transaction management. - Returns MCP Server: https://developer.avalara.com/products/returns/mcp.md — returns management, filing calendars, and compliance data. - Cross-Border MCP Server: https://developer.avalara.com/mcp-servers/cross-border.md — HS code classification, duty calculations, and trade and tariff content. - E-Invoicing MCP Server: https://developer.avalara.com/products/e-invoicing/mcp.md — document statuses, downloads, and live reporting. - ECM MCP Server: https://developer.avalara.com/products/ecm/mcp.md — certificates, customer profiles, and company data. - Communications MCP Server: https://developer.avalara.com/products/communications/mcp.md — communications tax calculation and reference data. - Tax Content MCP Server: https://developer.avalara.com/products/avalara-tax-content/mcp.md — ATC data, TTE configurations, jobs, and lodging UDFs. - Business Licensing MCP Server: https://developer.avalara.com/products/registration-and-licensing/mcp.md — licensing, regulatory compliance, and industry data. - Developer Docs MCP Server: https://developer.avalara.com/mcp-servers/docs.md — Avalara developer documentation and API reference. --- # Integration Guides Source: https://developer.avalara.com/ Step-by-step guides for integrating Avalara into different platforms and workflows. Choose the guide that matches your integration type for platform-specific best practices. Core: ERP (https://developer.avalara.com/erp-integration-guide/about-this-guide/), eCommerce (https://developer.avalara.com/ecommerce-integration-guide/about-this-guide/), Marketplace (https://developer.avalara.com/marketplace-integration-guide/about-this-guide/), Hospitality (https://developer.avalara.com/hospitality-integration-guide/tpd6373686358981/), Communications (https://developer.avalara.com/products/communications/integration-guides/communications-integration/), Managed Returns US/Canada (https://developer.avalara.com/products/returns/integration-guides/managed-returns/), Managed Returns EMEA (https://developer.avalara.com/products/returns/integration-guides/managed-returns-emea/). Product-specific: Account Provisioning (https://developer.avalara.com/account-provisioning/lxk1686163423564/), Address Validation (https://developer.avalara.com/address-validation/mge2528064649525/), AvaTax and ECM (https://developer.avalara.com/avatax-dm-combined-erp/about-this-guide/), AvaTax for Accounts Payable (https://developer.avalara.com/avatax-for-ap/xai0106202356926/), Beverage Alcohol (https://developer.avalara.com/avatax-for-bevalc/bevalc-about-this-guide/), Cross-Border Customs Duty and Import Tax (https://developer.avalara.com/products/crossborder/integration-guides/avatax-for-cdit/), ECM (https://developer.avalara.com/products/ecm/integration-guides/document-management/), Excise (https://developer.avalara.com/products/excise/integration-guides/excise/), E-Invoicing and Live Reporting (https://developer.avalara.com/products/e-invoicing/integration-guides/elr/), 1099 & W-9 (https://developer.avalara.com/products/avalara-1099-and-w9/integration-guides/1099-and-w-9/), MyLodgeTax (https://developer.avalara.com/products/mylodge/integration-guides/mylodgetax/). VAT: Ecommerce (https://developer.avalara.com/vat-ecom/), ERPs (https://developer.avalara.com/vat-erp/), Marketplaces (https://developer.avalara.com/vat-marketplace/). Migration: SOAP to REST v2 (https://developer.avalara.com/soap-to-restv2-refactor-guide/), REST v1 to REST v2 (https://developer.avalara.com/restv1-to-restv2-refactor-guide/). --- # Developer Tools Source: https://developer.avalara.com/ - API Playground: https://developer.avalara.com/playground/ — test Avalara API calls interactively with live sandbox data. - Patch Notes: https://developer.avalara.com/patch-notes/ — release notes and changelog for Avalara APIs and products. - AvaTax Error Codes: https://developer.avalara.com/avatax/errors/ — searchable list of error codes with resolution steps. - API Versioning: https://developer.avalara.com/api-versioning.md — how Avalara versions APIs and handles breaking changes. --- # Certification Source: https://developer.avalara.com/certification/ Partner certification programs validate that integrations meet Avalara quality standards. Certification is required for partners listing on the Avalara marketplace. - Certification Overview: https://developer.avalara.com/certification/ - AvaTax Certification: https://developer.avalara.com/certification/avatax/ - CertCapture Certification: https://developer.avalara.com/certification/certcapture/ - Communications Certification: https://developer.avalara.com/certification/communications/ - Excise Certification: https://developer.avalara.com/certification/excise/ --- # Getting Started and Support Source: https://developer.avalara.com/ - Free Trial / Sandbox: https://developer.avalara.com/freeTrial.md - Developer Community: https://community.avalara.com - Avalara Support: https://help.avalara.com - Avalara Website: https://www.avalara.com - Terms of Use: https://www.avalara.com/terms-of-use/ - Sitemap: https://developer.avalara.com/sitemap.html --- # API Endpoint Deep Links Source: https://developer.avalara.com/llms-api-endpoints.txt For per-endpoint markdown documentation (individual method .md files with parameters, schemas, and curl examples), fetch the full endpoint index: https://developer.avalara.com/llms-api-endpoints.txt Each product's bundled API reference is also available as a single .md file: - AvaTax REST API v2: https://developer.avalara.com/products/avatax/api.md - Communications Tax API v2: https://developer.avalara.com/products/communications/api.md - Excise Tax API v1: https://developer.avalara.com/products/excise/api.md - AvaTax Brazil API: https://developer.avalara.com/products/avatax-brazil/api.md - Tariff Code Classification API: https://developer.avalara.com/products/item-classification/api.md - E-Invoicing API: https://developer.avalara.com/products/e-invoicing/api.md - Activation Service API: https://developer.avalara.com/products/activation-service/api.md - ECM API: https://developer.avalara.com/products/ecm/api.md - Shared Services API: https://developer.avalara.com/products/shared-services/api.md - Registration and Licensing APIs: https://developer.avalara.com/products/registration-and-licensing/api.md