Do a moonlight/midnight flit
Definition 1 of 1
Pro Tip 1/3Sudden Departure
This phrase implies leaving with urgency and often by night to avoid detection. 
After losing his job, Joe decided to do a moonlight flit to avoid his creditors.
Pro Tip 2/3Secretive Action
The action is done in secrecy, without informing anyone, especially those expecting payment. 
The tenants did a midnight flit to avoid confrontation with the landlord.
Pro Tip 3/3Avoiding Debt
The phrase often refers to escaping financial obligations such as unpaid rent or bills. 
They did a moonlight flit from the hotel, leaving a hefty bill unpaid.