Is the Price Guardian compatible with the Tarifa Constante?

No. The Price Guardian is available exclusively to Tarifa Transparente customers.

If you switch to the Tarifa Constante, the Price Guardian is automatically deactivated and you become ineligible to activate it for as long as you remain on that tariff.

If you switch back to the Tarifa Transparente in the future, you'll be able to activate it again.