Fosti

At a glance

• Editor score
  3.0 / 10
• Pricing
  Paid
• Best for
  Tax firms managing client compliance operations
• Free plan
  No
• Paid from
  $4,300/yr
• Facts checked
  22 Sep 2026

• Where it wins

  • Covers calendars, workflows, portals, tracking, and audit trails
  • Integrates with Vertex, Avalara, OneSource, and other tax engines
  • Includes white-label client portals and multi-client compliance tools

• Where it doesn't

  • Starts at $399 per month with no free plan
  • Does not provide direct return filing or tax calculation
  • Email support is the listed channel on Starter

Our verdict on Fosti

Fosti is a cloud-based sales-tax practice management and compliance workflow platform for CPA firms handling multiple clients and states. Its 11 core modules cover filing calendars, client intake, five-step compliance workflows, white-labeled portals, nexus threshold monitoring, worksheet variance flags, filing and payment tracking, document management, escrow ledgers, time tracking, billing, profitability reports, and exemption-certificate tracking. The platform is suited to small, mid-market, enterprise, scaling, established SALT, and multi-office practices that need a shared operating layer for client compliance work.

Pricing starts with Starter at $399 per month or $4,300 per year, including all 11 core modules, a white-label portal, up to three team members, and email support. Growth costs $799 per month or $8,600 per year and adds unlimited team members, custom subdomain and branding, and priority support. Scale costs $1,499 per month or $16,200 per year, adding advanced analytics, dedicated onboarding, and a 99.9% uptime SLA. Enterprise includes everything in Scale, plus SSO and SCIM, custom integrations, and white-glove onboarding. This structure gives larger firms more operational and support capacity, but the entry price makes Fosti a substantial commitment for smaller practices.

Fosti’s ecosystem fit is a central part of its role. It integrates with Vertex, Avalara, OneSource, Sovos, TaxJar, NetSuite, QuickBooks, and Xero, while API access supports broader connectivity. The platform works alongside existing returns engines rather than replacing them, and filing support is assisted. That makes Fosti a strong choice for firms coordinating compliance operations across clients, states, documents, payments, and certificates. Firms seeking native tax calculation or direct return filing should choose a more complete tax-compliance platform instead.

Your product? Our editors can test Fosti in depth and publish a review, labelled as paid · from $149/mo →

Fosti pricing

All 4 Fosti plans and prices →

Fosti fact sheet

Fosti integrations

Fosti lists 8 integrations on its own site.

• Vertex
• Avalara
• OneSource
• Sovos
• TaxJar
• NetSuite
• QuickBooks
• Xero

Alternatives to Fosti

• ONESOURCE DeterminationA global indirect tax engine for complex, high-volume calculation needs.9.4
• CSCCH SureTaxA broad sales-tax platform for teams combining calculation, research, filing, and remittance.9.3
• ONESOURCE Indirect ComplianceA broad compliance platform for multinational tax and finance teams managing complex filings.9.2

See all Fosti alternatives →

Featured on iTechGuides

Fosti is listed in our Tax Compliance Software directory. Add the badge to your site — it links back to this page.

<a href="https://www.itechguides.com/products/fosti/"><img src="https://www.itechguides.com/best/badge/fosti.svg" alt="Featured on iTechGuides" width="230" height="46"></a>

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Last updated 7 Oct 2026 · How we research and update