The United States built its e-signature framework around two pillars: the federal ESIGN Act and the state-level UETA.

The Electronic Signatures in Global and National Commerce Act (ESIGN, 2000) is the federal law that established e-signature validity nationwide. It's deliberately technology-neutral and provider-neutral: there's no requirement to use a specific signature technology or a domestically certified provider, which is unusual compared to jurisdictions built around a tiered system like the EU's eIDAS.

The Uniform Electronic Transactions Act (UETA, 1999) is a model state law that fills in the state-level detail underneath ESIGN. It's now been adopted, by name, in 49 states, including Illinois and Washington, which each ran their own separate electronic-transactions statutes for years before formally enacting UETA in 2021 and 2020. New York is the only holdout: it still relies on its own Electronic Signatures and Records Act (ESRA, 2000) rather than adopting UETA. In practice ESRA reaches a similar result to UETA, though its excluded-document list runs a little broader, barring e-signatures on all individually executed trusts and powers of attorney rather than just wills.

Signature Types Recognized

Unlike eIDAS, US law doesn't define separate signature tiers. Both ESIGN and UETA test validity against the same four requirements regardless of the technology used: intent to sign, consent to conduct the transaction electronically, association of the signature with the record being signed, and the ability to retain and reproduce that record. There's no second tier of "advanced" or "qualified" signatures required for higher-stakes documents.

Firma.dev's signing flow meets the same security bar that eIDAS calls SES and AES, though US law has no equivalent classification for it: any valid electronic signature works the same way here.

US law handles exclusions differently: a short, named list of document types sits outside ESIGN/UETA's scope entirely, regardless of signature method. Wills, codicils, and testamentary trusts, court orders, documents requiring notarization, and a handful of consumer-protection notices (utility and insurance cancellation, foreclosure on a primary residence, product recalls) fall into this category. Everything else, including commercial contracts, NDAs, employment agreements, and real estate leases, is fair game for standard e-signatures.

Industry-specific rules layer on top of this baseline rather than replacing it. HIPAA adds authentication, audit trail, and encryption requirements for documents containing protected health information, typically alongside a Business Associate Agreement with the platform. FDA 21 CFR Part 11 adds unique signer identification, audit trails, and system validation requirements for FDA-regulated electronic records. Neither changes what counts as a valid signature under ESIGN/UETA; both add controls on top of it.

For SaaS companies, agencies, and internal teams building or using signing workflows in the US, the practical result is straightforward: standard e-signatures cover commercial contracts, NDAs, employment paperwork, and vendor agreements without any special signature tier, and the main things to track are the narrow document exclusions and the sector-specific overlays for healthcare and life sciences.