Signing on behalf of someone else.
Powers of attorney, representation and systems acting for people.
A large share of the signatures produced every day do not bind the person who signs, but someone else: a company, a public agency, a client, a minor. The manager signs for the company, the attorney in fact for the principal, the invoicing system for the business that operates it. It is not enough for a signature to be authentic; it must also be shown that the signer was entitled to sign on someone else's behalf.
Identity is not authority
A certificate proves who a person is. It does not prove what that person is allowed to do. María may hold an impeccable certificate and, at the same time, lack the authority to bind the company to a contract of that size. Confusing the two is one of the most frequent mistakes in designing signing processes, and one of the most disputed afterward.
| Question | What answers it |
|---|---|
| Who signed? | The signer's identity and credential. |
| On whose behalf? | The represented entity or person, identified unambiguously. |
| With what authority? | Bylaws, powers of attorney, appointments or mandates, with their scope and term. |
| Within what limits? | The type of act, the amount, the term, and whether the signer acts alone or jointly. |
The forms of representation
- Statutory representation. Whoever holds an office in a company or public body acts on its behalf according to its bylaws or governing rules. The authority arises from the office and ends with it.
- Power of attorney or mandate. One person authorizes another to carry out certain acts. Its scope is set out in the text of the power of attorney, which may be broad or very narrow.
- Internal delegation. Within an organization, someone with authority distributes it by amount, department or document type. This usually lives in an internal policy and changes often.
- Attributes in the credential. Some certificates include the signer's position or the representation. It is convenient, but the attribute stays fixed until the certificate expires or is revoked, even if the authority changed earlier.
When a machine signs
Not everything that gets signed is signed by a person. Invoices, certificates, attestations and records are issued automatically, thousands a day. That is what entity signatures or organization seals are for: they attribute the document to an organization rather than to an individual. The European eIDAS Regulation calls them “electronic seals” and distinguishes them from signatures, which only a natural person can produce.
The question becomes more interesting when a system acts on behalf of a person: an assistant that accepts terms, a program that negotiates and closes orders. The law already has an answer in principle. The 2005 United Nations Convention on the Use of Electronic Communications in International Contracts provides that a contract shall not be denied validity solely because an automated system was involved without human review of each action. The practical consequence is clear: what the system does is attributed to whoever set it in motion, within the limits they established for it.
What to do
- Verify authority at every signature, against an up to date source, not only when the credential is issued.
- Record in the evidence on whose behalf the signature was made and on what basis.
- State the limits of each delegation: acts, amounts, terms and joint signatures.
- Revoke authority at the very moment the position changes or the mandate ends.
- For automated systems, document who authorized them, for what purpose and within what limits.
Identity says who signs; authority says on whose behalf and how far. Statutory representation, powers of attorney, delegations and automated systems all require the same thing: a verifiable basis at the moment of signing, explicit limits, and a record that makes it possible to reconstruct, years later, why that signature bound someone else.