Sigma Tax Pro review
A seasonal tax and bookkeeping suite for small practices handling 1040, 1120, and 1065 returns.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Sigma Tax Pro is professional tax preparation software for independent tax preparers, CPAs, accountants, and tax offices. Its packages cover individual 1040 returns and business returns using Forms 1120 and 1065, with federal and state filing capabilities. The platform combines tax preparation with e-filing, printing, online return storage, file conversion, review and error correction, refund estimation, and an EIN database. It also includes Client Write-Up accounting with bookkeeping, payroll, and accounts payable and receivable modules.
Pricing is seasonal and plan-specific. Sigma 1040-TW and Sigma 1040-SR each cost $495 per season. Both include federal and state business income tax returns, old-file conversion, Client Write-Up, automatic updates, and filing-status comparison; 1040-TW adds a built-in Interview Wizard, while 1040-SR offers Step-by-Step Interview or Forms Method input. Sigma 1040-DR costs $895 per season and adds desktop and web-based versions, e-filing with long-term online storage, multi-office management, and support for Forms 1120 and 1065.
The strongest fit is a small practice that wants tax preparation and bookkeeping capabilities in one product, particularly when file conversion, return review, and integrated bank products matter. The plan structure gives preparers options for individual-return workflows while reserving broader business-return and multi-office capabilities for the higher-priced 1040-DR package. Practices that need entity coverage beyond individual 1040 returns and Forms 1120 and 1065 should consider a broader alternative. The product is also less suitable for buyers seeking a free plan or a non-seasonal pricing model.
Sigma Tax Pro pros and cons
- Where it wins
- Supports federal and state returns with e-filing, printing, and storage
- Converts files from other tax software and includes return review tools
- Adds bookkeeping, payroll, accounts payable, and accounts receivable modules
- Where it doesn't
- Seasonal pricing starts at $495 with no free plan
- Entity support centers on Forms 1120, 1065, and individual 1040 returns
- Multi-office management and web access are included in the $895 1040-DR plan
Sigma Tax Pro fact sheet, pricing and score →
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