Simple authorization letter: what it is, what to include and how to sign it

A simple authorization letter (known in Spanish as carta poder simple) is a private document in which one person (the grantor) authorizes another (the agent) to carry out a task on their behalf: pick up a document, cash a check, file papers at an office. It doesn't go through a notary, which is why it's quick and free.

The simple letter is for minor acts and administrative errands. To sell property, represent someone in court or sign high-value acts, the law usually requires a notarized power of attorney. Before writing it, ask the institution which kind it accepts: that alone saves most wasted trips.

Place and date. Full name and ID of the grantor and the agent. The specific task being authorized, described precisely ("pick up my son's transcript at school X" is better than "handle paperwork"). The validity period, if any. And the signatures.

In many countries, such as Mexico, it's customary for two witnesses to sign as well, with their names. Some offices also ask for copies of the IDs.

"In [city], on [date]. I, [grantor's name], holder of [ID], hereby grant full and sufficient authority to [agent's name], holder of [ID], to carry out [specific task] before [institution] in my name and on my behalf. Grantor's signature, agent's signature and, where applicable, two witnesses' signatures."

For dealings between individuals and with many companies, yes: an electronically signed authorization letter with its audit trail proves who signed and when. What's worth confirming is whether the institution where you'll present it accepts electronically signed documents; some public offices still require paper with a handwritten signature.

With Firmiu you can send it for signature to the grantor, the agent and the witnesses — up to 5 signers — and each one signs from their phone. Paid plans also include a power-of-attorney template: fill in the details and the document is generated ready to send.