Putting it another way, if there is any problem with any permission that might be required, you will soon hear about it from ATC when you speak to them.
300?nm west of India a few years ago, contacting Trivandrum and providing them with ADC number.
T - "Please confirm your aircraft type is 747?"
Us - "Negative A320"
T - "Your clearance is for a 747, clearance not available. Turn right remain outside of Indian airspace...."