Wiktionary
n. (context UK English) An amount of money paid by everyone or every user of something.
Wikipedia
The Flat Rate refers to “A charge or level of payment that is the same in all cases”. This regards the regular amount a person is charged, whether it be in a given time period or per use. For example, in a majority of fitness centres, a person who is interested in signing up for the first time usually has to pay a specific signup fee. This fee is considered to be the Flat Rate that consumers pay, or is also known as the “Flat Fee”. Though it is subject to change, the pricing will never fluctuate per consumer or use. Flat rates stay the same regardless of amounts of customers. A flat fee, also referred to as a flat rate or a linear rate, refers to a pricing structure that charges a single fixed fee for a service, regardless of usage. Rarely, it may refer to a rate that does not vary with usage or time of use. Another term used is "flate", a hybrid of "flat" and "rate".
Flat interest rate mortgages and loans calculate interest based on the amount of money a borrower receives at the beginning of a loan. However, if repayment is scheduled to occur at regular intervals throughout the term, the average amount to which the borrower has access is lower and so the effective or true rate of interest is higher. Only if the principal is available in full throughout the loan term does the flat rate equate to the true rate. This is the case in the example to the right, where the loan contract is for 400,000 Cambodian riels over 4 months. Interest is set at 16,000 riels (4%) a month while principal is due in a single payment at the end.
Usage examples of "flat rate".
Because the local government had hired the Frisians at a monthly flat rate, cost cutting had a direct, one-to-one effect on President Hammer's profit margin.
Hollywood was merely a specialized bank--a consortium of large financial entities that hired talent, almost always for a flat rate, ordered that talent to create a product, and then marketed that product to death, all over the world, in every conceivable medium.
More, for the first time in the Star Kingdom's history, Parliament had, with much trepidation, adopted a graduated income tax rather than the Constitutionally-mandated flat rate.
There was money to be made out of the business, with very little capital required for plant, while surplus destroyers and submarines could be bought at a flat rate of one pound per ton, subject to the condition that they had to be broken up.
In fact, some drilling contractors just quoted this as a flat rate.
See, back in the original Callahan's Place, Mike Callahan had a flat rate: every drink in the house cost a dollar-and if for some reason you decided not to smash your emptied glass in the fireplace, you were entitled to take two quarters' change out of the cigarbox on the end of the bar on your way out.