I don't understand, what really constitutes a "won't let me quit" scenario? If I hand in my resignation, I don't really care whether my employer rips it or not. I consider my contract terminated because it's a contract that can be terminated by either party to the contract. If I have a notice period, I'll work that period, then stop showing up. If they want to consider the contract as still valid, they can. And then they'd have to pay me, but I don't see why they would if I'm not turning up to work? There must be something in the above reasoning that isn't correct?