Having to do a lot of research etc into flying overseas and one country that's got it spot on is Ireland. You have to register your drone with the IAA which is a simple and actually quite well designed online login/form. You can have multiple UASs registered, including their serial numbers etc, and when applying for flight permission you select which UAS it's with, use the embedded map to find long/lat (which also shows restricted areas), and provide details of what you'll be doing and when.
Was super easy to use and also quite useful. Can't imagine it would cost any more than 100k with a big web agency to provide a similar service.
Link for those interested:
https://www.iaa.ie/general-aviation/drones/drone-registration