Custom Tenancy agreement

Hi, I have recently found tenants for my flat using OpenRent. When trying to proceed using the OpenRent contract, we cannot select option to pay 6 months rent upfront as it exceeds the 12k limit. In addition to this, I need to add the clause stating the rent for further 6 months will be paid upfront at 6 month mark of the 12 month tenancy. I have tried Lawpack agreement but they do not seem to have this provision either. How do I find the appropriate contract to use and proceed on OpenRent using the custom contract please? Many thanks, Kal

You may still need a monthly agreement and figure but a clause to say it is payable every 6 months.