Privacy Policy

Who we are

BillKit (billkit.app) is an online invoice, quote and receipt generator operated by an independent developer based in Taiwan ("we", "us"). We are the controller of the limited personal data described in this policy. You can reach us at [email protected].

Your documents stay on your device

Everything you type into the generator — your business details, client details, line items, logo, notes and the PDFs you download — is processed locally by JavaScript in your browser. It is not sent to us or to any third party.

To make the tool convenient, the generator saves your work in your browser's local storage on your device, for example:

• your draft document and preferences (currency, language, template);
• your logo, saved clients, item library and document history (Pro features);
• your Pro license information (key billkit_license: license key, device activation ID, plan and when it was last verified).

This data never leaves your device unless you export it yourself. You can delete it at any time by clearing the site data for billkit.app in your browser settings. Because we never receive it, we cannot recover it for you either — keep copies of important PDFs.

Data we process when you visit

Our site is hosted on Cloudflare. Like any web host, Cloudflare processes technical data such as your IP address, browser user agent, requested URL and time of the request to deliver pages and protect the site against abuse. These logs are short-lived and we do not use them to identify you.

We may use Cloudflare Web Analytics to understand which pages are popular. It is privacy-friendly: it does not use cookies or local storage, does not fingerprint visitors and only gives us aggregated statistics (page views, referrers, country, device type).

Payments and Pro licenses

Pro purchases are processed by Lemon Squeezy, which acts as the merchant of record and reseller of BillKit Pro. When you buy, you provide your name, email address, billing country and payment details directly to Lemon Squeezy, which processes them under its own privacy policy. We never see or store your full card details.

Lemon Squeezy shares with us the order information we need to provide the service and support: your name, email address, country, the plan purchased, order and subscription status, and your license key.

When you activate or re-verify Pro (about once every three days), your browser sends your license key and a device activation ID to our license endpoint, which checks it with Lemon Squeezy's license API. A short label describing your browser and operating system (for example "Chrome on Windows") is stored with the activation so you can recognize your devices. No document content is ever included.

Advertising

To keep the free plan free, we may show ads from Google AdSense on content pages (guides and templates) — never inside the invoice editor, and never to Pro users. If ads are enabled, Google and its partners may use cookies or similar technologies to serve and measure ads, including personalized ads based on your visits to this and other websites.

Visitors in the EEA, the UK and Switzerland are asked for consent through a Google-certified consent banner before personalized ads are shown. You can manage ad personalization at Google Ads Settings and learn more at How Google uses information from sites that use its services. You can also opt out of many third-party ad networks at aboutads.info or youronlinechoices.eu.

Affiliate links

Some pages recommend third-party tools, such as payment or accounting services, through affiliate links that are clearly labeled. If you sign up through one, we may earn a commission at no extra cost to you. These links may carry a referral code and utm_source=billkit, and the partner may set its own cookies once you reach its site, under its own privacy policy. We never share your documents or personal data with affiliate partners.

AI features

Some optional features use AI, for example turning a short description into invoice lines or drafting a payment reminder. When you use one, the text you typed and the invoice details you chose to include are sent through our server to Anthropic's Claude API to generate the result, which is returned to your browser. BillKit does not store this text. We only keep short-lived usage counters (per IP address, deleted after 2 days) to prevent abuse and, for Pro users, a hashed license key for 24 hours to apply the higher limit. Anthropic processes the request under its commercial terms, which by default do not allow using API data to train its models. Please don't enter information you don't want to share.

Cookies and local storage

BillKit itself does not set tracking cookies. We use your browser's local storage only for the functional data described above. Third parties may set cookies when you use their features: Lemon Squeezy when you open the checkout, and Google if ads are enabled and you have consented where required. You can block or delete cookies in your browser; the generator will keep working.

Legal bases (EEA/UK)

• Performance of a contract — processing order and license data to provide Pro.
• Legitimate interests — hosting logs and aggregated analytics to run, secure and improve the site.
• Consent — personalized advertising cookies, where required by law. You can withdraw consent at any time.
• Legal obligation — keeping transaction records where the law requires it.

Retention

Data in your browser stays until you delete it. Order and license records are kept by Lemon Squeezy and by us for as long as your license is active and afterwards as long as needed for accounting, tax and legal purposes. Support emails are kept as long as needed to help you and then deleted.

Sharing and international transfers

We do not sell your personal data. We share data only with the service providers named in this policy (Cloudflare, Lemon Squeezy and, if ads are enabled, Google), who may process it in countries other than your own, including the United States, under appropriate safeguards such as standard contractual clauses.

Your rights

Depending on where you live (for example under the GDPR, UK GDPR, Taiwan's Personal Data Protection Act or US state privacy laws such as the CCPA/CPRA), you may have the right to access, correct, delete or export your personal data, to object to or restrict processing, to withdraw consent, and to opt out of the sale or sharing of personal data for targeted advertising. To exercise these rights, email [email protected]. You also have the right to lodge a complaint with your local data protection authority.

For purchase data held by Lemon Squeezy you can also contact Lemon Squeezy directly.

Children

BillKit is a business tool and is not directed to children under 16. We do not knowingly collect personal data from children.

Changes to this policy

We may update this policy as the service evolves. We will change the "last updated" date above and, for significant changes, show a notice on the site.

Contact

Questions about privacy? Email [email protected].