Flights to the UK via the Republic of Ireland
Student visitors who are non-visa nationals who choose to travel to the UK without applying for a visa/entry clearance before they travel should not enter the UK via Dublin.
The Republic of Ireland has a ‘Common Travel Area’ with the UK. This means there is no immigration presence on arrival in Edinburgh or Glasgow from Dublin. As such you cannot apply for the visiting student category through this route and would be in the UK only as a tourist for a maximum of 90 days.
Tourists are not permitted to study and the University would not enrol you on your course. You would need to leave the UK to a location outside of the Common Travel Area (Amsterdam, Paris and Frankfurt for example) to return and legally apply as a Student Visitor.
If you have a Tier 4 (General) student visa before travelling, you can travel through Dublin. However please keep copies of your boarding pass and flight tickets for your journey from Dublin to Edinburgh/Glasgow. This can later be used as evidence of your arrival date in the UK.