If my passport is valid for another three years but I've run out of?
Doesnt matter how long is passport is valid for adding more pages to a passport is something I havent heard of. From my research I can tell you that Australia, Canada, India & United Kingdom simply require you to apply to be issued a new passport if your existing no longer has any blank pages. Till 2014 american nationals could request new visa pages for their passport in 24 page packets (maximum of 2 packets) however that has since been phased out.