It is your responsibility to be absolutely sure that your passport has the correct validity for your chosen destination, as most countries now require passports to be valid 6 months beyond the intended date of departure from that country.
Always check whether you need an entry visa to the country you are visiting. It is your responsibility to ensure that you have the required visa to enter or pass through all the countries you are planning on visiting.
If you are travelling with a group of different nationalities or citizenships, then each person must double check the entry requirements from the Governments foreign travel advice pages. It is important to know that visa regulations can be regularly changed, therefore check for the latest up to date information.
Some countries require an electronic travel authority which can be done online. The authorisation is then electronically linked to your passport. Please note that even if you are in transit, some countries still require an electronic travel authority, for example just passing though the USA to an onward destination but not actually staying there overnight, just waiting for a connecting flight. Although it would still be required to pass though customs and immigration.
Parents or adults travelling alone with children under 12 years of age require documentary evidence of permission to take children abroad. All children and infants must travel with their own passports.
Note: It is highly recommended before a trip to take photocopies of your passports and other important documents and keep these separate from the originals.