What is a fair use policy (FUP)?
A fair use policy is the limit hiding behind the word unlimited. Here is what it typically caps, how to read one before buying, and what happens when you cross it.
A fair use policy, usually shortened to FUP, is the set of limits that applies to a plan sold as unlimited. It exists because no network can actually carry unlimited traffic, so "unlimited" in mobile data almost always means "unlimited at some speed, after some amount".
Reading one before you buy is the difference between a plan that suits you and a plan that stops being useful on day two.
What a FUP normally limits
Three things, and most policies use at least one:
A daily allowance at full speed. The most common shape on travel plans. You get a few gigabytes per day at normal speed, and after that the connection is slowed, often heavily, until the next day resets it. A slowed connection still carries messaging and maps; it usually will not carry video calls.
A total cap. Less common on day passes, more common on monthly plans. Cross it and the line stops rather than slows.
What the data can be used for. Tethering is the usual one: some unlimited plans allow it only up to a smaller separate allowance, or not at all.
The slowed speed is the number that matters and the one least often published. There is a real difference between being reduced to something that still loads a map and being reduced to something that cannot.
How to read one before buying
Four questions. If a provider's page does not answer them, that is itself information.
- How much at full speed, and over what period? Per day and per plan are very different.
- What speed afterwards? A figure in megabits, not the word "reduced".
- Does it slow down or stop?
- Is tethering included, limited, or excluded?
Why providers do it at all
Not only to protect margins, though that is part of it. A handful of heavy users on a shared cell can measurably degrade service for everyone else on it, and roaming capacity is bought in wholesale blocks with real limits.
The honest version of the argument is that the policy is what makes the headline price possible. The dishonest version is printing "unlimited" in large type and the policy in small type, which the industry has done for long enough that regulators in several countries now have rules about it.
Our own unlimited plans carry a daily allowance at full speed, and we put the figure on the plan itself rather than in a footnote, because it is the thing that decides whether the plan fits your trip.
Quick answers
Does unlimited data really mean unlimited?
In practice, no. It normally means unlimited at a reduced speed once you pass a daily or total threshold. The threshold and the reduced speed are the two numbers that matter.
What happens when I hit a fair use limit?
Usually the connection is slowed rather than cut. On some plans it stops until the next day. Which one it is should be stated in the policy.
Does a fair use policy reset?
On most travel plans with a daily allowance, yes, at a fixed time each day. On plans with a total cap there is no reset within the plan.
Is tethering covered by unlimited?
Not always. Some plans include it, some give it a separate smaller allowance, some exclude it. It is worth checking separately, because it is the clause most often treated as an exception.