Bills and payments
Why the Octopus app and your bill do not match
Common reasons the usage or cost shown in the Octopus app differs from your bill, and how to tell which figure to trust.
Edited by Rob Gibbs. Published: . Guidance reviewed: .
Short answer
The app shows smart meter data as it arrives, and can show gaps, delayed half hours or an estimated cost. The bill uses validated readings, the exact tariff prices for each period, standing charges and VAT. When they disagree, the bill is the figure you are charged. Missing smart data is the most common cause.
Common reasons for a mismatch
These cover most cases:
- Missing half hours: if the meter did not send some readings, the app shows gaps that the bill fills from validated meter readings.
- Standing charges and VAT: an app usage figure may show only the energy cost.
- Price changes: a tariff or price change part-way through the period means two sets of prices on one bill.
- Timing: the app and the bill may cover slightly different days.
- Export: on an export tariff, payments and charges appear separately.
Which figure to trust
The bill. It is built from validated readings and the tariff terms. Use the app to spot patterns and gaps. If the app shows the meter has stopped sending data, report it and send manual readings.
Checking it yourself
You can download your half-hourly data and price it against the published rates for your region using this site’s private usage tools. They run in your browser. If your total is far from the bill, raise it with Octopus with your figures.
Questions people ask
Why does the app show less usage than my bill?
Usually because some half-hourly readings did not arrive. The bill fills those gaps from validated meter readings.
Can I check an Agile bill myself?
Yes. Price each half hour of your usage at that half hour’s published Agile rate, then add the standing charge. The usage tools on this site do that for you.
Tariffs in this guide
Related guides
- Is Agile Octopus actually cheaper?When Agile Octopus beats a standard tariff, why the answer depends on when you use power, and how to check with your own half-hourly data.
- What happens to your smart meter when you switch to OctopusWhether your smart meter keeps working when you switch to Octopus, why some older meters go dumb, and what to do about it.
- What is Octopus Energy? Tariffs and how it differsA plain-English introduction to Octopus Energy: who it is, the kinds of tariff it offers, and how to find the right one for your home and region.
- How Octopus Energy Direct Debit payments are worked outHow Octopus sets your monthly Direct Debit, why it reviews it, and how to change the amount or date without building up debt.
- Octopus account in credit or debit: what it meansWhat it means when your Octopus account is in credit or debit, when to ask for a refund and when to change your Direct Debit instead.
- Economy 7 or single rate: which is cheaper?When Economy 7 beats a single-rate tariff, the night share that decides it, and how to check with today’s Octopus rates for your region.
Primary sources
- Joining an Octopus smart tariff — Octopus Energy; checked 2026-08-27. Smart-meter connectivity, half-hourly readings, installation and compatibility limitations.
- Domestic energy supply terms and conditions — Octopus Energy; checked 2026-08-24. General domestic tariff, meter, pricing, switching and referral terms.