What is KBA, and when do you need it?
Knowledge-based authentication checks a signer's identity before the document opens, by asking questions drawn from public records. Most teams who need it already know they do, because the requirement comes from their own regulatory context, most often in accounting and tax. It is an authentication choice you make per document, not a setting you turn on once.
What is knowledge-based authentication?
KBA verifies that a signer is who they say they are before the document opens. The signer answers a short set of questions drawn from public records, three of five in the Verdocs implementation, and only reaches the document once they pass. It is available for US signers.
When do you need KBA?
Usually you already know. The requirement tends to come from your own regulatory context rather than from us, and in practice it lands most often in accounting and tax work. It is tied to documents where identity matters more than convenience: IRS forms, high-value transactions, and contracts where a disputed signature would be expensive.
Does Verdocs pre-fill the KBA questions from my data?
No, and this is the most common misunderstanding. You do not send us personal data to seed the questions. The recipient enters their own details at signing time, and the questions come from a third-party identity provider working from public records. Verdocs orchestrates the step; it does not hold the identity dataset behind it.
What does the signer actually go through?
They complete a short form, then answer the questions, then the document opens. It runs inside the same signing flow, so there is no separate portal, no second login, and no handoff to a site that looks nothing like yours.
What does KBA cost?
It is priced per use rather than bundled, because the identity check has a real cost behind it that we pass through. Current per-use pricing sits with the other identity add-ons on the pricing page. Whether to spend it is your call, per document.
Going deeper on KBA
Is Knowledge-Based Authentication Enough for Remote Signing?
IRS Publication 1345 requires KBA and also points at a NIST assurance level. Reading both documents carefully shows why that question has no clean answer.
Read the post2026-10-09KBA for Form 8879: Designing Identity Checks Clients Finish
IRS Publication 1345 sets the identity rules for signing Form 8879 remotely. Whether clients finish depends on how tax software prepares them, enforces the failure path, and handles joint returns.
Read the post2026-08-22Product Requirements for Remote Signing of IRS Forms 8878 and 8879
IRS Publication 1345 contains a build spec for remote signing of Forms 8878 and 8879. Its nine software developer requirements, restated for product teams.
Read the post2026-10-09Matching Signer Verification to the Insurance Transaction
Not every insurance document needs the same signer check, and document type alone should not decide it. A starting matrix for matching checks to the signer, the requested action, and the money involved.
Read the postKBA is one of eight authentication levels, from an emailed link up to a live ID scan. The full ladder and the evidence each step leaves behind are on the compliance page, and per-use pricing sits with the other identity add-ons on the pricing page.
General information, not legal or tax advice; consult your own advisors for the requirements that apply to your documents.