Security and data handling

How FlagSage keeps your information safe, mostly by never receiving it.

Short answer

The free tools run entirely in your browser. Your answers are never sent to FlagSage, never put in page addresses, and never logged. There are no accounts, no uploads and no tracking scripts.

What the site does

Served over HTTPS only, with strict transport security
A content security policy that allows scripts only from this site
No third-party scripts, fonts, analytics, chat widgets or advertising
No document uploads, no accounts and no forms that send tax information

What the tools do

The rule file is the only thing they download
Answers stay in memory, or in your browser's local storage if you turn that on for the ledger
Exports are created in your browser and saved straight to your device
Restoring a backup reads the file in your browser only

What we ask of you

Don't email us tax documents, ID numbers or account details. We don't need them and won't ask for them.

Report a security issue

Email hello@flagsage.com with "Security" in the subject.

Countries: No country rules on this page
Tax year: No tax-year claim applies
Coverage: Current coverage register
Last updated: November 8, 2026