I am travelling to the UK on a tourist visa (valid for 6 months) in about 10 days.
I also have the BIVS stamp on it and wish to travel to Dublin. Is it possible, as my friend who lives in the UK and has a PR there says even she can't unless she has an Irish visa? And that we can only travel to the Northern Ireland.
According to the first point in this document (accessed 8 March 2018 from the Irish Department of Foreign Affairs website: https://www.dfa.ie/) it would seem that you will be able to travel to the Republic of Ireland with a BIVS-endrosed valid short-stay visa:
"The British-Irish Visa Scheme allows for mutual recognition of short-stay visas between the UK and Ireland. This means that a British short stay visa will be valid for travel onward to Ireland, and an Irish short-stay visa will be valid for travel onward to the UK. Visas that are valid for use under this scheme will have ‘BIVS’ endorsed on them."
As for traveling to Northern Ireland, there should be no issue whatsoever, as Northern Ireland is part of the UK.
However, it may be the case that your friend cannot travel to Ireland, depending on her visa. This is based on my personal knowledge of 2 people (1 Japanese and 1 Chinese) who lived and worked in Ireland under long-term visas, but could not travel to the UK without obtaining a UK visa.
This suggests that the BIVS does not apply to long-term or working visas.
Under the BIVS scheme, you can indeed visit Ireland with your UK short-term visa. Details available here: https://www.gov.uk/government/publications/british-irish-visa-scheme/british-irish-visa-scheme
However your friend has a different type of visa, which does not include automatic authorisation to enter Ireland, and she must indeed apply for a visa.
