I'm a Vietnamese passport holder so I need to apply for visa to enter Schengen area this October. The main purpose of my trip is to join company training in Belgium with Brussels to be my port of entry. However since I'd be arriving early Friday, I'd like to fly to Oslo to visit my friend over the weekend first and will stay at her place before actually joining the training in following week.
My questions are:
(1) Does my friend need to provide me with an invitation letter with her signature and confirmation from local authority on her residency status there?
(2) Will she need to mail the paperwork to me in Vietnam?
(3) Does she need to send along copy of her passport, visa and proof of ownership of the property? My friend is Vietnamese, has lived in Oslo for 5 years and now works there under skilled worker visa. She also owns the place that I would be staying (bought it with her Vietnamese husband, still paying mortgage installment).
For 2-day visit, I really don't want her to skip work and go to local office for such hassle. If having such invitation letter is a must, is there any other alternative option for me to prove my accommodation during my trip to Oslo? (Maybe book then cancel the hostel booking? I'm not sure if it's OK to do so).