Nationals of all Western European countries can visit United Kingdom without a visa; US, Canadian, and Australian passport holders can stay up to 90 days without a visa.
Depending on your nationality, a visa is required when intending to travel to United Kingdom. All visas must be applied for prior to departure at the nearest United Kingdom Embassy or United Kingdom Consulate in the applicant's country of residence.
To determine whether or not you require a visa to visit the United Kingdom, please visit the UK Visas and Immigration website, following their "Check if you need a UK visa" link. On the same site, you will find explanations as to the category of visa and ways to obtain them.
SPIE recommends that you secure your travel visa before registering for the conference as cancellations after the preregistration cutoff date may result in a cancellation fee.
Letter of Invitation
FOR CONFERENCE CHAIRS, TECHNICAL COMMITTEE MEMBERS, AND AUTHORS: Individuals requiring letters of invitation to obtain travel visas must be listed on a paper or in the programme to receive an invitation letter. If you are listed in the conference programme and need an Official Invitation Letter from SPIE for visa application purposes, please submit the completed Invitation Letter Form and send it to invitationlettersEU@spieeurope.org.
FOR EXHIBITORS: If you are an exhibitor requiring a letter of invitation from SPIE to obtain a travel visa to participate in the Exhibition, please fill out and send the Exhibitor Invitation Letter Request Form.