Privacy notice

Marginrule runs marginrule.com and sells Excel pricing workbooks through Payhip. Marginrule is run by Stephen Register, sole proprietor. This notice explains what we collect and why.

What we collect

When you buy or download a workbook. Payhip provides the checkout page and delivery, including for the free Lite workbook. We receive your email address, what you got, the price you paid, your country, and any answer you give at checkout, such as agreeing to our licence. We never see your card details. Payhip checkout pays into the seller's PayPal account, including card payments made through PayPal. Payhip's privacy policy covers what Payhip collects, and PayPal has its own.

When you email us. Your email address and what you write, so we can answer.

When you visit the website. We don't use analytics or set tracking cookies. Our host, Cloudflare, processes basic technical data such as your IP address to deliver the pages and protect the site from attacks, under its own privacy policy. The calculators run in your browser, and the numbers you type are not sent to us.

How we use it

To deliver what you bought, handle refunds, answer your emails and keep records that tax rules require. If we fix a workbook or update its fee presets, we may email past buyers about it through Payhip.

We don't send marketing emails at the moment. If we start, we will ask first, and every email will have an unsubscribe link.

We don't sell or rent your details to anyone.

Who else handles it

Payhip for checkout, delivery and sales tax and VAT. PayPal for payments into the seller's account. Cloudflare for hosting the website. Porkbun forwards email sent to our address. Each keeps data under its own privacy terms, and some of them store data outside your country, including in the United States and the United Kingdom.

How long we keep it

Order records are kept as long as tax rules require. Emails are kept as long as we need them to help you, then deleted.

Your choices

You can ask what we hold about you, ask us to fix it, or ask us to delete it. Email help@marginrule.com. Depending on where you live, you may have more rights under local law, and you can complain to your data protection authority.

Changes

If this notice changes, the date below will change too.

Marginrule, help@marginrule.com. Last updated 14 Nov 2026