BBasis

In February 2026 Basis said it had shown the first AI agent to complete an end-to-end Form 1065 partnership tax return on its own. The New York startup builds agents for accounting firms that run multi-hour accounting, tax and audit jobs in the background and hand back finished work for an accountant to check.

Its CEO estimated in July 2026 that Basis is deployed at about 40% of the top 25 US firms. Named customers include UHY, Clark Nuber, MarksNelson and Boulay.

How It Works

Basis connects to a client’s general ledger, accounting system and documents, then works through tasks the way a staff accountant would. On the tax side it maps trial balances to return lines, pulls K-1 data with footnotes, drafts M-1 adjustments and fixed asset roll-forwards, and checks finished returns against source documents. For client accounting it cleans up ledgers, drafts journal entries, runs reconciliations and builds reports such as a 13-week cash forecast. Audit agents run testing procedures and generate workpapers.

The platform ships with more than 350 pre-built procedures, and firms can write their own. Entries are staged for review before posting, and every agent action is logged with its sources and reasoning. Firms usually adopt it across a whole practice area, and a deployment team helps staff test it on workflows they know well.

Pricing

Basis does not publish prices. Access starts with a request form or waitlist and a conversation with sales, and there is no free plan or self-serve trial on the pages reviewed.

What to Watch Out For

Security is a strength on paper. Basis lists SOC 2 Type II, ISO 27001 and ISO 42001 certification, US data hosting and per-client data isolation, and says client data is not used to train models. GDPR and CCPA are still marked as coming soon, which matters for firms with European clients. The site does not name the specific ledger or tax software it connects to, so firms should confirm support for their stack. Efficiency claims of 20% to 50% come from an investor, not an independent study.

Recent News

Basis raised $100 million at a $1.15 billion valuation in February 2026, in a Series B led by Accel with GV and Khosla Ventures. In July 2026 its CEO described the company’s expansion from outsourced accounting into tax and audit, noting a new partnership with Top 50 firm Sikich and a staff of 120 people in New York.