Must tether be used when this seat is rear facing?

Hi Rachell, thank you for your enquiry, the Britax Boulevard G4 does have a tether strap is provided.  Britax recommends using this when forward facing as it increases stability, however, the seat has been tested both with and without using the tether, and it complies with the USA standard both with and without using the tether.  It can, therefore, be safely used with or without attaching the tether.