You can enter the UK with either a valid passport or a national identity card issued by a EEA country. It must be valid for the whole of your stay.
You must have a valid passport to enter the UK. It must be valid for the whole of your stay.
You may also need a visa, depending on which country you’re from. To check if you require a visa visit the gov.uk website here https://www.gov.uk/check-uk-visa
If you need an official letter to confirm your attendance at ISTP 2017 in order to obtain a visa, please contact email@example.com