FUP: Why "Unlimited" Plans Still Have a Limit

Home internet is sold with the word "unlimited" in the largest type on the page, and a small asterisk in the corner. That asterisk points at a paragraph which says, roughly: once usage reaches a given amount, speed will be adjusted to a given percentage.

That paragraph decides what you are actually buying. And it is almost always read late, usually in the third week, when video stops loading and not one light on the router looks wrong.

What is unlimited is not the speed

FUP stands for Fair Usage Policy. The mechanism is simple: while your monthly usage stays under a threshold, the speed matches your plan. Once you pass it, the speed is reduced until the next billing period begins.

Notice what does not happen there. The connection is not cut. There is no extra charge. You may still download as much as you want. That is why the word "unlimited" can still be used: the data is unlimited.

What is limited is the speed, and speed is what you actually experience day to day. The gap between 50 Mbps and 10 Mbps is not a difference in brochure figures; it is the difference between a clear video call and a stuttering one.

Why the limit exists at all

The reason is not stinginess but how networks are built. A provider does not install capacity equal to the sum of every customer's plan. If a thousand customers subscribe to 100 Mbps, no provider is holding 100 Gbps ready for them.

That ratio is called the contention ratio, and the whole industry runs on it. It rests on the fact that customers neither use the network at the same moment nor use it at full tilt: most of the time you are reading a page, typing, or not online at all.

The arrangement works well until a small group of customers uses the network almost continuously, large downloads all day, every day. A handful of those on one segment is enough to slow down everyone sharing it. A FUP is a way of restraining that extreme use without disconnecting anybody.

What deserves scrutiny is not that a FUP exists, but how plainly it was stated before you signed.

Reading the numbers before you subscribe

Three numbers decide everything, and all three belong in the terms of service. If one of them is missing, that absence is itself an answer about the provider.

• The threshold. How many gigabytes of monthly use before the speed drops.
• The speed afterwards. Usually given as a percentage of the plan speed, and often tiered, one drop at the first threshold, another at the second.
• When the count resets. Nearly always the billing period, not the first of the month.

A threshold only means something once you compare it with your own usage. A rough guide for one household: high-definition video runs about 3 GB per hour, and 4K roughly three times that. Video calls run about 1 GB per hour. Browsing, messaging, and music barely register beside those.

A family watching four hours a day approaches 400 GB a month from video alone. Compare that with the written threshold, not with a feeling that "we don't use much".

Telling a FUP from a fault

Slow internet has many causes and a FUP is only one of them. Distinguishing them matters because the response is completely different, one calls for a change of plan, the other for a fault report.

Three fairly reliable signs:

• Consistent all day. A FUP knows nothing about peak hours. If it is just as slow at three in the morning, that is a deliberate cap, not congestion.
• It stops at a similar number. Repeated tests land near the same figure, say, always around 10 Mbps, because that is where the limit is set.
• Starts mid-month, recovers at rollover. A repeating monthly pattern is the strongest sign of all.

By contrast, slowing only between 7pm and 11pm and improving near midnight points to network congestion. Speed that wanders with no pattern, with the connection dropping now and then, is more often a device or cabling problem.

Confirming it yourself

A hunch is not enough to take to support. What ends the argument is a record.

1. Open your provider's app or customer portal and note usage for the current period. Compare it with the threshold in the terms.
2. Test speed from a device on a cable where possible, so Wi-Fi is not another variable.
3. Repeat at three different times, morning, evening, and the small hours, on the same day. Record the time and the result.
4. Repeat once more the day after the billing period rolls over.

If the three results are uniform and jump the moment the period resets, you have your answer, and the evidence with it.

What actually helps

No trick makes a FUP not apply; it is counted on the provider's side. What remains is managing usage and choosing a plan with the right numbers.

• Lower the default video resolution. Moving a television from 4K to 1080p cuts usage by up to two thirds, and on an ordinary screen the difference is hard to see.
• Schedule large downloads. Console updates and file backups run to tens of gigabytes. Some providers exclude overnight usage from the count; check the terms before relying on it.
• Find what uploads quietly. Photo sync and cloud backup run unasked, and on some services count in both directions.
• Re-do the plan arithmetic. If you hit the threshold every month on a similar date, the plan is simply too small. Moving up one tier is often cheaper than buying top-ups repeatedly.

What you can insist on

A FUP may be applied, but it may not be hidden. What is reasonable to ask for, and reasonable to be given:

• Written terms stating the threshold, the reduced speed, and the reset date, not a verbal explanation from an agent.
• Your own usage figure, checkable at any time, not only on the bill.
• Notification before or when the threshold is passed.

If the speed drops while your usage is clearly below the threshold, that is not a FUP and must not be answered as one. At that point your measurements become the basis of a fault report.

What to do

"Unlimited" is a promise about data, not about speed. The FUP is where those two are separated, and it always lives in the terms of service, never in the brochure.

Reading it before subscribing takes two minutes. Discovering it in the third week, when video stops loading and nothing appears to be broken, takes considerably longer.

Frequently asked questions