How Tax Shrink handles your data
Tax Shrink has no accounts and does not send financial inputs to analytics. Some information still reaches our hosting provider when you open a calculator URL, and emailed enquiries are processed by our email provider.
Last updated 21 August 2026.
Who controls your data
Bold Data Ltd is the data controller for Tax Shrink. Bold Data Ltd. Company no. 13328783. Registered in England and Wales. Registered office: Elderleigh, Highfield Close, Northwood, England, HA6 1EX. Contact tax-shrink@bolddata.biz with a privacy question or request.
Calculator inputs and browser storage
Calculations run in your browser. Tax Shrink stores company profit, prior-year distributable reserves, the planned reserve dividend and the selected Income Tax region under the browser key taxShrinkStore so those choices survive a reload. This remains until you clear site data for tax-shrink.com, remove it through browser settings or the browser removes it. Salary in the personal calculator, other dividend inputs, derived tax rules and results are not persisted in that store.
Calculator URLs can contain company profit, salary, dividend, prior-year distributable reserves, the planned reserve dividend and region. When you open a shared URL, its full request, including those parameters, reaches Vercel, our hosting provider. It can also remain in browser history, bookmarks, copied messages and systems used by anyone with whom you share it. Remove the query string after ? before sharing if you do not want those figures in the link.
The live project uses Vercel Pro. Vercel runtime logs can expose request search parameters and, under the current plan, retain those log entries for up to one day. Access is limited to authorised project and Vercel personnel. See Vercel's runtime-log documentation.
Privacy-focused analytics
We use Plausible to understand aggregate use and improve the service. Before an event is sent, Tax Shrink replaces the page URL with its origin and path and reduces any referrer to its origin. Query parameters, financial values, Income Tax region, custom properties and application logs are not sent to Plausible. We count aggregate visits to each calculator and the methodology, plus clicks from a company result to its personal-tax breakdown. The click event has no properties, so it does not identify which result was viewed.
Plausible uses no cookies or persistent identifiers for this service. It processes aggregate device and referral information and processes visitor data in the EU. Its daily identifiers are not designed to follow a person across sites or days. Read the Plausible data policy.
Emailed enquiries
Google Workspace processes messages sent to tax-shrink@bolddata.biz, including the address, content and attachments you choose to send. Please provide only the minimum information needed to reproduce an issue. We ordinarily retain enquiry correspondence for up to 24 months after the last meaningful contact, unless law or an active dispute requires longer retention.
Why we process this information
Our legitimate interests are operating a secure and reliable estimator, understanding aggregate demand, answering enquiries and correcting errors. We balance those interests by keeping calculations in the browser, stripping analytics query strings, collecting no analytics custom properties, limiting access and retention, and not using calculator data for advertising or automated decisions with legal or similarly significant effects.
Processors and international transfers
Vercel hosts the website, Plausible provides analytics and Google Workspace provides email. Plausible visitor data is processed in the EU. Vercel and Google may process information in the UK, EEA, United States or other locations under their contractual safeguards and applicable transfer mechanisms. We do not sell personal data.
Deletion and your rights
Clear this site's browser storage to delete local calculator preferences. You may ask us for access to, correction or deletion of personal data we hold, or ask us to restrict processing or consider an objection. These rights depend on the circumstances and applicable law. Email tax-shrink@bolddata.biz; we may need enough information to confirm your identity and locate the relevant correspondence.
You may also complain to the Information Commissioner's Office. You can review the terms of use and the calculator's methodology and scope for related safeguards.