Last Updated: 16th June 2026
Welcome to plan58.co.uk. We provide isolated, interactive financial simulation tools covering specific UK financial mechanics, including the High Income Child Benefit Charge (HICBC), retirement bridging timelines, and investment versus debt overpayment comparisons.
We take a strict "privacy-by-design" approach. This policy outlines exactly how your data is handled, ensuring you retain full control over your financial information.
Legal Entity & Registration: Plan58 is a trading name of Dominic Wilkinson, operating from the United Kingdom. For the purposes of UK GDPR, Plan58 acts as a Data Controller for subscriber account data, and strictly as a transient Data Processor for end-user lead generation contact data submitted via embedded widgets.
1. Local Client-Side Processing (No Passive Tracking)
The primary calculations on this website are executed 100% locally client-side within your own web browser context.
No Passive Logging: We do not use real-time tracking scripts, keystroke loggers, or background form tracking. As you type numbers, move sliders, or interact with our tools, no data is passively captured or transmitted over the network.
No Hidden Server Storage: Your inputs vanish the moment you close or refresh the page.
Shareable Links: If you choose to use a "Copy Shareable Link" feature to save a scenario, your inputs are compiled purely into URL parameters copied to your clipboard. This data remains entirely within the link string and is not stored on our servers.
2. Embedded Lead Gen Widget (Third-Party Webmasters)
This website allows external website owners (Subscribers) to embed a lead-generation version of our fully functional simulators on their own platforms or hosted landing pages.
Zero Financial Data Transmission: All calculations performed by Plan58's embedded calculators run entirely within the visitor's browser. No financial inputs, including income figures, pension values, investment amounts, or personal financial data of any kind are transmitted to or stored by Plan58 or the Subscriber.
Configuration Requests: When an embedded calculator loads, it makes a single, lightweight configuration request to Plan58 servers to retrieve display settings (such as the Subscriber's trading name, regulatory status, and whether the lead form is active). This request contains no financial data and no visitor-identifying information whatsoever.
Lead Capture via Email Routing: If the optional lead capture form is enabled and configured for Email Routing, only the contact details voluntarily submitted by the visitor (first name, last name, email address, optional telephone number, and preferred contact method), along with routing metadata (calculator name, UTM parameters), are processed. This data is relayed to the Subscriber's nominated email address via our secure third-party email sub-processor. Transient delivery logs containing these contact details are securely retained by our sub-processor for a maximum of 30 days to ensure reliable delivery, after which they are permanently purged. Strictly no financial data is included in these email payloads.
Lead Capture via Webhook Routing (Pro/Growth Tiers): Paid Subscribers may route leads directly to their own CRM infrastructure. To protect endpoint URLs from public exposure, this routing is handled via a secure, server-side transient proxy. When a visitor submits the form, the payload (strictly limited to contact details, the calculator name, and UTM parameters) is transmitted to Plan58’s routing application entirely in-memory. No financial inputs or calculator results are included in this payload. Plan58 does not write, log, or persist this payload to any database, file system, or storage medium. The data is instantly forwarded to the Subscriber's HTTPS endpoint and permanently destroyed from Plan58 server memory upon completion. Plan58 acts solely as a transient technical conduit; the Subscriber's own privacy policy governs how the resulting contact data is handled.
3. Web Analytics
To monitor overall site health, traffic volume, and long-tail search visibility, we use standard web analytics (Google Analytics 4). This software tracks aggregate visitor movements (such as page views and button interactions) but does not record individual financial entries, names, or personal identifiers. GA4 is only activated after a visitor has provided explicit consent via our cookie banner (see Section 4).
4. Cookies and Local Storage
We use the following types of cookies and browser storage on this website:
Strictly Necessary: A secure, encrypted session cookie (
p58_portal) is set when a registered Subscriber logs into the Plan58 customer portal. This cookie is required solely to maintain the authenticated session and is automatically deleted upon logout. It is markedHttpOnlyandSecure, meaning it is never accessible to third-party scripts or client-side JavaScript.Functional / State: Local browser storage is used by our interactive calculator tools to preserve your current dark/light mode preference between visits. This data exists only within your browser and is never transmitted to our servers.
Analytics (requires your consent): We use Google Analytics 4 to monitor aggregate site traffic, page health, and long-tail search visibility. GA4 operates under Google Consent Mode v2: all analytics signals are set to denied by default when you first visit the site. GA4 will only begin collecting data after you explicitly click "Accept" on the cookie banner. No analytics data is collected during a session in which you have clicked "Decline" or have not yet responded to the banner.
You can withdraw or change your analytics consent at any time by clicking "Manage Cookie Preferences" in the footer of any page. You may also clear or block cookies at any time via your browser settings without affecting the mathematical functionality of any calculator on this site.
5. Regulatory & Financial Guidance Disclaimer
Plan58 is not authorised or regulated by the Financial Conduct Authority. These tools constitute unregulated, illustrative mathematical models only:
Purely Illustrative Models: This website provides illustrative mathematical simulations only. The tools simply execute deterministic mathematical formulas based entirely on the hypothetical data you choose to input.
Accuracy and Estimation Disclaimer: While we strive to ensure the underlying mathematical formulas are structurally sound, all outputs are estimations only and we do not guarantee 100% accuracy. These simulations may contain calculation errors, omissions, or assumptions that do not perfectly reflect actual outcomes. Do not rely on these numbers for precise financial tracking or auditing.
No Advice or Recommendations: The outputs generated by these tools do not constitute financial advice, formal recommendations, or endorsements of any financial strategy.
No Circumstance Review: Because your data is processed locally, this platform does not, and cannot, assess your personal or wider financial circumstances. For specific financial planning or advice, always consult an independent, FCA-regulated financial professional.
6. Contact Information
Plan58 is the Data Controller for personal data relating to our registered Subscribers. For privacy-related enquiries, or to exercise your data protection rights (including access, rectification, or erasure), please contact us at [Insert Contact Email].
You also have the right to lodge a complaint regarding our data processing activities with the UK Information Commissioner's Office (ICO) at ico.org.uk.
7. IFA Subscriber Account Data
If you are a financial adviser, accountant, or website owner who has registered to use the Plan58 Embed Service, we collect and store the following information to manage your account and maintain platform integrity:
Email address (used as your account identifier and for sending magic-link login emails).
The domain(s) you have registered to embed Plan58 calculators.
Your self-declared regulatory status, Firm Reference Number (FRN), and associated automated FCA register API verification logs (where applicable).
The domain-matched email address used strictly to authorize your professional registration status.
Your subscription tier, acceptance timestamp of the Terms of Service, and Stripe subscription reference (payment card data is held exclusively by Stripe; Plan58 never processes or stores card details).
Your trading name and privacy policy URL, for display in the embedded calculator's dynamic compliance footer.
Your nominated lead notification email address and securely encrypted webhook URLs.
This data is retained for as long as your account is active. You may request deletion of your account and associated data by contacting us. Closing your account will remove your domain registrations, regulatory verification status, and subscriber settings, causing any active embeds to revert to Free tier functionality.
Billing is handled exclusively by Stripe. Please refer to Stripe's Privacy Policy for information on how your payment data is processed.