It is strongly recommended that the consent letter be notarized, especially for international travel, so that the authenticity of the letter will not be called into question.
Notary Public Signing: To be of full effect, this document should be sworn and signed before a Notary Public. Do bring government issued identification and the child's birth certificate. DO NOT sign this consent form before meeting with the Notary Public.
Witness Signing: It is possible that signing before a Witness instead of a Notary Public will be adequate. However, we recommend you check the current policy of your airlines and/or the countries you are traveling to before taking this approach.
Note: If there is a custody order or death certificate, the original or a certified true copy should travel with the child.