Difference between ‘извините’ and ‘простите’

Both expressions verbalize our regret about something that happened due to our fault, but there is a nuance in their meanings. 

We say ‘извините’ (or ‘извини’ to close people) when the harm we do is not very serious. For example, you stepped on someone’s foot or you got to a meeting 5 minutes late.

We say ‘простите’ (or ‘прости’) when our fault is really bad. You might let someone down, break your own promise or cause great damage. In this case simple ‘извините’ would not be enough. 

If you want to concretize what you apologize for, use after ‘извините’ and ‘простите’ a preposition ‘за’ and Accusative case or the connecting phrase ‘за то, что’. Check some examples below.

• Пожалуйста, извините за опоздание! = Please excuse me for being late!
• Извини меня за то, что я вчера не позвонил. = I’m sorry I didn’t call yesterday.
• Простите за неудобства, это наша вина! = Sorry for the inconvenience, it’s our fault! 
• Прости меня, пожалуйста, за то, что не была рядом в этот тяжёлый момент. = Forgive me, please, for not being there at this difficult moment.