What is a Hard Kill

A Hard Kill disconnects your Google Cloud project from its billing account when spend crosses a threshold you choose. With no billing account, Google stops every paid resource in the project, so the bill stops growing.

It is the last line of defence: it works even if your code is broken, nobody is awake, or the spike comes from an attack you can't control.

• Every new budget starts with a Hard Kill at 100%, announced by email. You can move it to another threshold, or remove it if you only want alerts.
• It runs the first time the spend Google reports for the month reaches its threshold. See how budgets and thresholds work for how that is measured.
• If one update crosses several thresholds at once, FireShield runs the Hard Kill first, then the other actions. That way the alerts sent in the same update already say whether billing was cut, or that cutting it failed and you should check the project.
• It runs once per month. If it fails (for example, someone removed FireShield's role), it is retried with every new cost update Google sends until it succeeds.

• Everything in the project that needs billing: Cloud Run, Cloud Functions, Compute Engine, paid API calls and the rest. Your service goes offline.
• A Firebase project without a billing account falls back to the no-cost Spark plan, so anything that needs the Blaze plan stops working.
• Google may delete resources in a project that stays without billing. If you run Cloud SQL or Data Connect, keep a daily backup so a cutoff can't cost you your data.
• Only the affected project is touched. The billing account itself and your other projects keep running.
• While the project is stopped, FireShield runs no other actions for it. The dashboard shows it as Kill switch executed.

• Stop spend at exactly 100%. Google reports costs with a delay of up to several hours, so by the time the report arrives the project may already be past the threshold. A Hard Kill caps the damage; it doesn't make the bill exact. If a runaway bill is your main fear, set it a little below 100%.
• Undo spend that already happened. Costs incurred before the cutoff are still billed.

When you link a project, you sign in with Google once and FireShield is granted the Billing Account Administrator role on that project's billing account. FireShield uses it only to disconnect billing. Linking billing back always uses your own Google account, never FireShield's, and every Hard Kill is recorded in the project's audit log.

• Fix whatever caused the spike first, or the project will start spending again as soon as billing is back.
• Press Reactivate on the project in the FireShield dashboard and sign in with a Google account that owns the project and has the Billing Account Administrator role. FireShield links the billing account back and resumes monitoring. You can also link it yourself in the Google Cloud console.
• The Hard Kill won't fire again this month at the same budget amount. To have it armed for the rest of the month, change the budget amount: that resets every action.

A Hard Kill is a guaranteed stop that takes your whole project offline. A Soft Kill is a signed webhook that asks your own service to degrade itself (pause batch jobs, turn off an expensive feature) while billing stays connected. Many teams use both: Soft Kills at lower thresholds to slow spend down, and a Hard Kill at the top as a safety net. See the Soft Kill integration guide.