Should the top tether be used when the seat is being used as a booster?

HI Sally, thank you for yoru enquiry, the Evenflow Secure kid has a tether that is required when is it used as a harnessed booster, when you are using it as just a booster the tether is recommended but not required. We hope this helps. ?For further information on this or any of our other products available, if you follow the link https://www.babyonthemove.co.nz/store-locations/ this will take you to our online store finder. Here you can find contact details for your nearest Baby On The Move Store where one of our team experts will be happy to assist you in your product search and help answer any further questions you may have. We hope this has helped with your query.