- One-off fees, paid at the start
- Intro months
- Standard months
- Real monthly cost: the total divided by the months
The idea in one sentence
1 short paragraph
We add up everything you would pay over the comparison term, then divide by the number of months. That single figure is the real monthly cost.
What goes into the total
2 short paragraphs
First, the promotional price for as long as the promotion lasts, then the standard price for the rest of the term. Second, mandatory fees, such as a set-up or activation charge that you cannot avoid. Third, credits that are guaranteed, such as a fixed bill credit written into the offer.
Spreading a one-off fee across the term is what makes a cheap-looking plan with a large upfront charge comparable with one that has none.
What we leave out
2 short paragraphs
We do not count optional extras, credits that depend on something you might or might not do, or anything we cannot confirm from the offer. If a figure is unknown, we say so rather than guess.
That means your own bill can differ: taxes, optional add-ons, equipment you choose to buy and price changes announced after we last checked are not part of the number.
Why not just use the headline price?
1 short paragraph
Two plans can both advertise the same monthly figure while one jumps in price after a few months. Averaging over the full term shows that difference up front.
Common questions
Does effective monthly cost include taxes?
Our calculation uses the prices, mandatory fees and guaranteed credits in the offer data. Check the provider's own page for how tax is shown.
Why does the number differ from the provider's advertised price?
The advertised price is usually one moment in the contract, often the promotional period. Ours averages the whole comparison term, including the standard price and mandatory fees.
Up next · step 2 of 8 in ‘Start here’
Promo price vs standard price
What happens when an introductory deal ends, and how to see the full picture before you sign.
