Consent letters are applicable in a variety of situations. Among those situations are giving permission to a babysitter to authorize needed medical attention, giving permission for your child to travel overseas with another relative or divorced parent, allowing another person or company to use your business trademark or allowing a minor to do a task the law doesn't entitle them to, like getting married. Laws vary by state on whether or not a notary needs to sign such a letter.
Address the letter "To Whom it May Concern" or, if known, the specific recipient of the letter.
Explain the task, trip or right for which you are granting permission, including expected dates if it involves travel. Include any information that the recipient might need to know. For example, in the case of giving permission for a babysitter to authorize medical treatment, include the child's insurance information and primary doctor.
Write a specific consent statement including the full names of both parties involved such as: "I, (insert full name) give my consent to (full name) to (activity)."
Sign and date the letter in front of a witness who is not the person you're granting permission. Ask the witness to sign and date the letter.
Notarize the letter in cases of international travel or in states that require it of consent letters. Ask your bank if it has a notary, as many banks offer this service to their customers.