It is VERY likely that the adult travelling with an infant WILL be asked for identity, AND to prove a parental relationship with the child. I'm sure you can work out why for yourself, considering the possibility for child abduction my estranged parents (or worse!).
I'm speaking from experience, as both myself and my partner travel alone with our youngster who is now 19 months old, and this applies both internally in the UK, and with external flights abroad (to a much greater extent!).
Policy DOES vary, and only the airline you intend to fly with can advise accurately, as rules change constantly... but arrive at the airport without ID/proof, and there is a good chance you will be refused access to board the flight.
ANY sense of something suspicious, for whatever reason, and you WILL end up talking to the police!
No, you do not need a passport to fly within the United States of America. If you are going out of the country, you will need to get one.
You can fly anywhere within the borders of your current country.
A Canadian who is already in the United States does not need any special documentation to fly within the US. A Canadian passport or driver's license will suffice. There is no need for a visa.
You don't need a passport to fly within the continental US or your birth certificate.
Probably not, but you will need it getting back to the US.
You need a passport to cross from America to Canada. While inside Canada, you don't need your passport, except for ID purposes.
only within your own country, you will need a pass port for any destination outside your own country.
NO. You do not need a passport to fly within Canada.
You can fly to almost any major city in Western Europe from Amsterdam within 2 or 3 hours.
I'm not sure about an id for travel within the United States. A Passport is for international travel only, you will not need one if you fly to any of the 50 US states
Absolutely! every one needs ID to fly domestically, and everyone must have a passport when they fly internationally.
None needed to travel within the US.