Why am I being asked to pay ground rent?

If you are being asked to pay Ground Rent it is because your Lease says you have to.
Ground rent is a contractual rental payment to the owner (Freeholder or Head lessee) of the land on which your development is situated.
Unlike your Service Charge, Ground Rent is not related to the provision of any services.
You may either pay Ground Rent directly to the Freeholder, or alternatively we will have been instructed to collect these funds on behalf of the Freeholder.