Budgeting stored in your own Google Drive
When you sign in with Google, Bufin writes your budget as JSON files into a hidden application folder inside your own Google Drive. Bufin's servers never receive a copy of those files.
What the app folder is
Google Drive gives every app an optional private area, the app-data folder. That only that app can see. It is inside your Drive and counts against your storage, but it doesn't clutter 'My Drive' and other apps can't read it. Bufin uses only that folder. It never asks for permission to read your other files, so it couldn't open your documents or photos even if it wanted to.
What Bufin can read
Its own files, while you have the app open and a valid Google token in your browser. There is no server-side job that walks your Drive, and no copy of your budget on our side to walk. What our server does hold is the account record described on the security page.
Taking access away
Revoke Bufin at myaccount.google.com/permissions and the app can no longer read or write anything. The files stay in your Drive, and an export you took stays yours. This is worth knowing before you sign in: the exit is a Google setting, not a request to us.
Microsoft OneDrive works the same way
Signing in with Microsoft uses your OneDrive's app folder instead, with the same boundaries and the same revoke-from-your-account exit. Everything else in the app is identical.
Content last reviewed 2026-08-18