It looks like I may need to apply for one of these. What was your experience when doing so?
Just tried doing so, and the application process has asked me to notify my mortgage provider and not apply until i have done so. Another bit of protracted life admin costing £600 for the joy of doing it. 
I’m a decent landlord, property is of a good standard, tend to any repairs quickly and not increased the rent ever in the several years since the tenants moved in several years ago - how is this admin and cost of any real benefit?
TIA for allowing me to rant!