A signature is only worth what you can prove about it.
Anyone can put a picture of a name on a PDF. The question is what happens the day somebody says they never signed it. This page is the answer, in order.
Before the pen
- Consent, recorded
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Every signer reads the ESIGN and UETA disclosure and agrees to sign electronically. The version of the disclosure they agreed to is kept with the record, not just the fact that they clicked. Read the disclosure
- A code by email
Six digits, sent to the address on the lease — for a tenant, the address the landlord listed them under, which the server enforces and the client cannot talk it out of.
- Then a code by text
A second six digits, to the phone number on the lease. Both checks pass, or nobody signs.
- The legal name comes from the lease
Not from whatever account happens to be signed in. The name on the signature is the name in the agreement.
The pen, and the order
You draw your initials and your full signature — finger, stylus or mouse — and place them on the pages yourself, seeing where each one lands.
Then the order: every tenant signs, in any order among themselves, and the landlord countersigns last. On that last signature the document is sealed and the finished PDF goes to everyone on the agreement.
The signature cannot be lifted back out.
A signed PDF that can be edited afterwards proves nothing. Four things stop that here, and none of them trusts the phone that sent the file.
- Every page is compared, pixel by pixel
The server flattens each stored version to page images and compares it with the one before. It must be identical everywhere except inside that signer's own signature slots. A word changed anywhere else and the signature is refused.
- Each signer has their own key
A P-256 elliptic-curve key per signer, signing over a SHA-256 chain that includes everything signed before it. Break one link and the chain no longer verifies.
- The finished chain is sealed
The server puts its own seal over the completed chain, so the record cannot be reassembled from parts.
- Four independent clocks
RFC 3161 timestamps over the final document's digest, from DigiCert, Sectigo, Apple and freetsa.org — four separate authorities, each with a revocation snapshot taken at the same moment. Trusting our clock is not required.
What lands in your inbox with the lease.
A completion certificate, generated once when the document is sealed and never regenerated. It is laid out the way people already expect one to look.
Per signer
Legal name, the verified email and phone, the times each code was sent and entered and the addresses they were entered from, the consent record, the moment of signing, and a picture of the signature they drew.
Per document
The integrity record and the hash chain, the seal, a sub-block for every timestamp authority that answered, the events along the way, and a plain description of how the document was made.
Verifiable without us
Each signer's public key is printed in the certificate in a form standard tools read. A third party can check the signature against the document without contacting TenantBinder, and without our permission.
Kept
The disclosure pages are appended to the certificate itself, so the document and the terms it was signed under travel together.
What these signatures are.
TenantBinder signatures are made under the US ESIGN Act and UETA, the law that makes an electronic signature as binding as an inked one for a residential lease in the United States. In the vocabulary the European rules use, they are advanced electronic signatures: tied to one signer, made with a key only that signer used, and linked to the document so that any later change to it is detectable.
They are never qualified signatures. That is a different instrument: a certificate issued by an accredited European trust-service provider after an identity check in person or by an approved equivalent. A residential lease does not call for one, and an advanced signature is what the US ESIGN Act and UETA ask of it.
Electronic signing is available for properties in all 50 states and the District of Columbia. Some states cap how long a lease signed electronically may run, and the app tells you when yours does — before you sign, not after. 50 states and the District of Columbia
Signing something today?
If you were sent an invite link, you can read the lease, ask for changes and sign it in your browser — nothing to install, nothing to pay.