Commercial Agreement

General information for the business: We are a UK FCA Authorised Payment Institution that provides currency and payment services to personal and business customers
Industry: Business
Legal topic: Contract
Description of legal work: We need to draw a standard commercial agreement that will be used by us and customers of a service we are launching.
Extra notes: The agreement needs to reflect the FCA conduct of business terms and include clauses relating to early termination inside the initial term i.e. 24 months that our customer is liable for the 50% of the revenue had generated during the previous 6- months for 6- months post termination. I would also like the agreement to be for 2 years initially and wondered whether it should include price breaks depending on volume or if this should be in an appendix? Perhaps there should be a standard agreement with an appendix that is bespoke to each customer. What advice can you give?