What Is a Starter Interrupt Device?

A starter interrupt device (also called a payment-assurance device) is hardware that prevents a financed vehicle from starting after the buyer has missed a payment and been warned. It is not a kill switch — it can never stop a car that is running.

How a starter interrupt works

It wires in-line with the vehicle’s ignition circuit and, on command, blocks the next start. A warning is sent first; if the buyer still does not pay, the next ignition is blocked until they do. A 24-hour emergency start code is available, and the dealer restores the vehicle in one click after payment.

Starter interrupt vs kill switch

A “kill switch” implies cutting an engine mid-drive — that is not what this is. A starter interrupt only acts at the next ignition and can never shut off a moving vehicle, which is central to using it safely and legally.

Is a starter interrupt legal?

In most states, yes, with proper written disclosure and consent. Rules vary — see the state compliance guide. Learn how it works on the starter interrupt system page.

Frequently asked questions

Is a starter interrupt the same as a kill switch?

No. It only blocks the next start at ignition and can never stop a running or moving vehicle.

Can it strand a driver?

A 24-hour emergency start code is always available, and dealers send a warning before any disable.

Is it legal?

In most states, with proper disclosure and consent. See the state compliance guide.