Avalara vs Thomson Reuters ONESOURCE: which fits your firm?
Avalara and Thomson Reuters ONESOURCE both quote pricing on request; Avalara lists solo, small and mid-size firms where Thomson Reuters ONESOURCE lists mid-size.
Prices and details verified May 1, 2026. Both records sit in Tax compliance and research and are compared on vendor-published specifications, the same way across every tool.
Avalara vs Thomson Reuters ONESOURCE side by side
5 of 13 dimensions differ. Rows marked "Differs" are where the two records do not match.
| Dimension | Avalara | Thomson Reuters ONESOURCE |
|---|---|---|
| Entry price | Quoted on request | Quoted on request |
| Pricing model | Custom quote | Custom quote |
| Free trial | Not listed | Not listed |
| Free plan | No | No |
| Firm size fitDiffers | Solo, Small, Mid-size | Mid-size |
| Built for | Accounting firms | Accounting firms |
| Specialisation | Tax | Tax |
| Automation profileDiffers | High volume, routine work | Mixed routine and judgment work |
| Deployment | Cloud | Cloud |
| Geo availabilityDiffers | US, UK, EU, Australia, Canada, Global | US, UK, EU, Canada, Global |
| Integrations listedDiffersBoth list: NetSuite, Sage. | 9 listed | 4 listed |
| Certifications | Not published | Not published |
| Support channelsDiffers | Phone, Chat, Email, Knowledge base | Phone, Email, Knowledge base, Community forum, 24/7 cover |
Which one fits your firm
Choose Avalara if
- Firms whose clients sell across many US states or international jurisdictions, especially e-commerce.
- Practices on QuickBooks, Xero, NetSuite, Shopify, Amazon, or Salesforce that need tax across each system.
- Firms that want a partner portal to manage tax compliance for multiple clients in one place.
Think twice about Avalara if
- Solo practitioners with one or two simple-jurisdiction clients. Avalara is sized for multi-jurisdiction complexity.
- Firms that want published pricing before talking to sales. Avalara is custom-priced and sales-led.
- Practices that want to try before committing. Avalara offers no free trial.
Choose Thomson Reuters ONESOURCE if
- Mid-market and large firms whose clients need ASC 740 income tax provision automation.
- Practices whose clients run SAP, Oracle, or NetSuite and need integrated indirect tax determination.
- Firms that handle transfer pricing documentation and country-by-country reporting for multinational clients.
Think twice about Thomson Reuters ONESOURCE if
- Solo practitioners or small firms. ONESOURCE is built for in-house mid-market and enterprise tax teams.
- Practices that want published pricing or a free trial. ONESOURCE is custom-quoted by Thomson Reuters sales.
- Firms whose clients are sole traders or small businesses. The platform's depth is overkill at low complexity.
What each one does
About Avalara
Avalara calculates, files, and remits sales tax, VAT, GST, and excise duties for your firm's clients across 190-plus countries. It connects to over 1,400 business systems and handles returns, exemption certificates, and 1099 forms so your team spends less time on compliance filings.
Best for firms whose clients sell across many US states or international jurisdictions, especially e-commerce sellers.
About Thomson Reuters ONESOURCE
ONESOURCE is Thomson Reuters' end-to-end corporate tax platform covering income tax provision, indirect tax determination, transfer pricing, and global tax reporting. It connects to major ERP systems and is designed for in-house tax departments and the accounting firms that serve them.
Best for mid-market and large firms whose clients need ASC 740 provision, transfer pricing, or country-by-country reporting.
Thomson Reuters ONESOURCE profileThomson Reuters ONESOURCE vendor site
Frequently asked questions
- Which is cheaper, Avalara or Thomson Reuters ONESOURCE?
- Neither publishes a price, so there is no figure to compare. Both quote on request, which means the only way to see the cost is to ask each vendor for a quote built around your firm size and volume.
- Do Avalara and Thomson Reuters ONESOURCE both offer a free trial?
- No. Neither Avalara nor Thomson Reuters ONESOURCE lists a free trial. Neither publishes a permanently free plan.
- Which one integrates with QuickBooks and Xero, Avalara or Thomson Reuters ONESOURCE?
- Avalara lists QuickBooks and Xero. Thomson Reuters ONESOURCE lists neither. Across their full published lists the two share 2 integrations: NetSuite and Sage.
- Which suits a smaller firm, Avalara or Thomson Reuters ONESOURCE?
- Avalara lists solo, small and mid-size firms and Thomson Reuters ONESOURCE lists mid-size firms. Firm size fit is the vendor's own positioning, so treat it as the starting point rather than a limit.