How BasilTax works

Three steps. Five minutes. A complete audit trail for any tax return.

1

Upload the same documents used to file

Drop your W-2s, 1099s, K-1s, brokerage statements, rental docs — whatever was used to prepare the return. PDF, image, or CSV. No formatting required.

For tax professionals: upload on behalf of a client, or invite them to upload directly into their portal.

Uploaded 7 documents:

W-2 (2025) .......................... 1 page

1099-B Schwab ........................ 14 pages

1099-DIV Vanguard .................... 1 page

1099-INT Chase ....................... 1 page

1098 Mortgage ........................ 1 page

Schedule K-1 ......................... 2 pages

1099-NEC freelance ................... 1 page

All documents ready for verification.

Audit Trail (sample)

1040 Line 1: Wages — $185,400

Source: W-2, Box 1, page 1 (confidence: 99%)

Schedule D Line 7: Net ST Gain — $3,800

Source: 1099-B Schwab, pages 2-14, 47 transactions

1040 Line 3b: Qualified Dividends — $4,210

Source: 1099-DIV Vanguard, Box 1b, page 1 (confidence: 98%)

2

Every number gets traced to its source

BasilTax reads every document, extracts fields with page references, and maps them to the corresponding lines on your tax return. Every dollar has a paper trail.

SSNs and personal identifiers are stripped before any AI processing. The math is deterministic — no "AI guessing" on the numbers.

3

Ask, share, or export

Ask questions in plain English and get answers cited to your actual documents. Share a portal link with your client. Export an audit-ready PDF that you can hand to the IRS if they ever call.

For firms: your client gets their own branded portal where they can self-serve answers — without calling your office.

You asked:

"Where did the $3,800 short-term gain come from?"

BasilTax:

Your net short-term capital gain of $3,800 comes from 47 transactions on your Schwab 1099-B (pages 2–14). Total proceeds were $142,300 with a cost basis of $138,500. The $3,800 difference flows to Schedule D, Line 7, and then to Form 1040, Line 7.

Ready to make your returns audit-proof?

Start with one return — free. See the audit trail for yourself.