For accountants, tax preparers & bookkeepers

Client tax data never leaves your office.

Fill tax forms, redact SSNs and account numbers, and pull tables out of client PDFs without the file ever being uploaded. AttachKit runs entirely in your browser — so a client's return is never copied to a server you don't control. Your PDF never leaves your browser — open DevTools → Network and watch: the file is never uploaded.

Why "in your browser" matters for client data

Most online PDF tools upload your file to their servers to process it. For a blank worksheet that's fine. For a client's 1040, a W-2, a brokerage statement, or a K-1, it means a copy of taxpayer information now lives on infrastructure you don't control — subject to their retention and their breaches, and outside the four walls of your practice.

AttachKit doesn't upload the file at all. The PDF is filled, redacted, and converted inside the browser tab you have open. The server never receives it — and most of the time isn't contacted at all. There's no server-side copy of a client return to retain or breach.

Don't take our word for it — check the network tab

You can verify this in thirty seconds, before busy season:

• Open any tool (try Redact).
• Open your browser's developer tools and switch to the Network tab.
• Drop in a client PDF and run the tool.
• Watch the request list. The file is never sent. The full technical account is on the security page.

The tools you actually reach for

Fill tax & client forms

Fill W-9, 1040, Schedule A, and more from the form library, with verified field maps where available. Save common client and firm details once and prefill in one click.

Redact PII so it stays redacted

Strip SSNs, EINs, and account numbers. With forensic scrub the text and images underneath are removed from the file — not just hidden behind a black box that can be lifted out. Re-open and search the export to confirm before you send it.

Pull tables into a spreadsheet

PDF → Excel extracts tables into a spreadsheet, typing numeric, currency, percent, and date cells where it can — all in the browser, nothing uploaded. Reconcile against the source before relying on it.

Where we're honest about the limits

A tool you'd trust with client data should tell you what it isn't:

• Not a CPA firm or the IRS. AttachKit is independent software, not affiliated with or endorsed by the IRS or any government body, and nothing here is tax or accounting advice. Always confirm the current form edition on irs.gov.
• Not a Qualified Electronic Signature. For forms with specific e-signature requirements, follow the official instructions.
• Conversions are best-effort. PDF → Excel always needs a human reconcile against the source before you rely on the numbers.

Frequently asked

Do my clients' files get uploaded to a server?

No. AttachKit fills, redacts, and converts the PDF inside your browser tab — the bytes never go to our server. You can prove it: open your browser's developer tools, switch to the Network tab, and run any tool. You'll see no upload of the W-2, 1040, or bank statement. The exceptions are the optional AI features (form auto-fill and Redact's PII suggestions), which send only the extracted text (never the file), and Local AI mode keeps even that on your own machine.

Is this confidential enough for client tax data?

Because the file never leaves your machine, there's no server-side copy of a client's return to retain, breach, or be asked for — the confidentiality posture is the same as working on the file in a desktop app. That keeps the handling of taxpayer information firmly inside your office. (The optional AI features send only extracted text, never the file; both are opt-in and clearly labeled, and you can ignore them entirely.)

Can I redact SSNs and account numbers so they're actually gone?

Yes. Draw redactions yourself or let optional AI suggest likely PII (it sends only extracted text, never the file). With forensic scrub enabled, the text and image content under each mark is removed from the saved file — not just hidden behind a black box that can be copied out. Always re-open and search the export to confirm before you send it.

Can I pull numbers out of a PDF into a spreadsheet?

Yes — PDF → Excel extracts tables into a spreadsheet entirely in your browser, with numeric, currency, percent, and date cells typed where it can detect them. Nothing uploads. It's a best-effort conversion; always reconcile the output against the source before relying on it.

Is AttachKit affiliated with the IRS, or is this tax advice?

No. AttachKit is independent software for working with PDFs — not a CPA firm, not the IRS, and not affiliated with or endorsed by the IRS or any government body. Nothing here is tax or accounting advice. Always confirm the current form edition and instructions on irs.gov.

Are the signatures valid for engagement letters and forms?

AttachKit produces PAdES-aligned electronic signatures suitable for ordinary business documents, plus a content-bound proof anyone can verify at attachkit.com/verify. It is NOT a Qualified Electronic Signature (QES). For forms with specific e-signature requirements (e.g. certain IRS authorizations), follow the official instructions for that form.