What is a uniform format category D visa for entry to a state in the European Economic Area (EEA)?
Several years ago, the EEA Member States introduced a uniform format visa vignette (a green coloured vignette, which all member states use). A category D visa is a long term visa, which is, for example, issued for studies, employment etc. in one of the member states. You can easily check if you have a category D visa because the letter D will have been printed on the vignette. Other category visas are, for example, A: Direct airside transit, B: visitor in transit and C: visit visa. A D visa is only issued for purposes that involve a longer stay (e.g. studies, employment, settlement etc.). Please note that in order to be eligible for the UK transit visa waiver arrangements, your D visa still needs to be valid (unless of course any of the other exemption criteria apply)!
You can find a photo of a blank EEA common format visa vignette on the website of the European Commission’s Department for Home Affairs here. A larger photo can be found here. In case of a category D visa, the letter D will be printed after “Type of visa” on these visa stickers.
Note: unlike other Member States, the UK uses the uniform format visa vignette for UK visa categories A, B, and C only. The UK uses a different sticker for category D visas.