They require valid photo ID. Their website will give a list of what you can use. It is best to just bring your passport for any travel anyway.
Yes
No, British passport holders do not need a visa to Austria. Same goes for all EU citizens, and Swiss citizens.
No, unless they fly in to Scotland from outside the UK.British and Irish citizens (but not British "nationals" from Hong Kong or other places overseas) can fly within the British Isles with a photocard driving licence.Other EU citizens can use their national ID card.Everyone else still needs a passport.
Puerto Rico is a territory of the US that doesn't require a passport for US citizens.
Nobody requires a passport to travel between London (England) and Scotland, as both are part of the UK.
UK nationals require a passport, but no tourist or business visa is required for a stay of up to three months for British Citizens. British Overseas Territories Citizens or British Overseas Citizens coming for tourism do not require a visa for stays of up to three months, while British Nationals (Overseas) do not require a tourist visa for a stay of up to one month.
If he is travelling on a south African passport he will require a Schengen Visa if visiting Holland or Germany. He will require a separate visa from for the UK if he wanted to visit there as well.
A US citizen does not require a visa to visit Dubai, only a current and valid US passport. Proper visitor documentation will be granted, free of charge, upon arrival of US citizens.
Yes you do need to carry your Passport...just incase you change your mind and want to fly to another country....hahhaa... Yes, in order to prove you are a British citizen and thus have the right to enter another EU country. As Britain does not issue ID cards, this is the only way to prove you are a British Citizen. Some countries require everybody (including their own citizens) to carry ID at all times. So you need your passport for that as well.
All international flights require a passport, except for European citizens travelling between European countries, who only require a national identity card. Internal flights generally require only government issued photo ID, such as a driving licence.
If you are from the UK, then you do not need a passport to enter the Republic of Ireland, as they are within what's known as the "common British travel area" - allowing citizens of the British Isles to travel freely within the areas. However RyanAir may require a passport to prove that you are a UK citizen. Your best bet is to call RyanAir customer service and ask them.
Yes, according to the Immigration and Checkpoint Authority of Singapore, Iranian passport holders require a visa in order to visit Singapore.