- A term used to refer to a service, fee, or rate that does not change or fluctuate
- A term used when discussing a financial context, where no interest or extra charges are applied to a payment
- The bank offers a flat rate on their savings accounts, regardless of the amount deposited.
- The monthly flat for the rental property includes utilities and maintenance costs.
- He was relieved when the car dealership confirmed that the price was a flat, without any added interest or fees.