Privacy policy
Last updated: 17 October 2026
This app is a Budget simulator. It is independent: it is not produced, endorsed or approved by HM Government, HM Treasury or the Office for Budget Responsibility.
The short version
We do not ask who you are, we do not collect personal data, and we do not track you. There are no accounts, no advertising and no analytics.
What stays on your phone
The Budget papers you write, any costing you keep for comparison, which challenges you have tried or met, which weeks you completed the weekly challenge (your streak), and whether you have seen the introduction are stored only on your device. So are the household details for “What it means for me”, but only if you choose “Remember on this phone”. They are never uploaded. Deleting the app deletes them.
What is sent to our server
To show the Budget map and to cost a paper, the app sends a request to our calculation service at number-11-engine.fly.dev. A costing or challenge request contains only the policy changes you chose (for example, “basic rate of income tax +1 percentage point”), the name of the challenge if you are playing one, and a version code for the data. It contains nothing about you or your device.
The one exception is “What it means for me”, which you choose to use. The household details you enter there (for example earnings, pension income, rent, number of children and age band) are sent to calculate your result and are not stored. They are used only to answer that one request, are not written to disk, logged or kept in the results memory described below, and are gone as soon as the answer has been sent. The app keeps them on your phone only if you turn on “Remember on this phone”, which is off unless you switch it on.
The service calculates the result and sends it back. To answer repeated papers faster, it keeps recent costing results in memory for a short time. They are not linked to you or your device, are never written to disk or logged, and are cleared whenever the service restarts. It does not keep an access log.
Sharing a Budget
Shared links contain only the Budget’s measures: nothing about you or your household, and we do not store them.
Reminders
If you ask for a reminder about Budget day, the app schedules a single notification on your phone. It is made and delivered by your phone, with no account, no push token and nothing sent to us.
Our hosting provider
The calculation service runs on Fly.io. As with any internet service, your device’s IP address is used to route the connection, and the provider may process it briefly for security and to keep the service running (for example, to limit abusive traffic). We do not use it to identify you, and we do not combine it with anything else.
Children
The app collects no personal data from anyone, including children.
Changes
If this policy changes, we will update this page and the date above. Any change that adds collection of personal data would be announced in the app before it happened.
Contact
Questions about privacy: support@urdev.dev.