First, you have to understand the arrangement and mechanism that operates between your organization and your mother company.
Your mother company 'out sourced' certain jobs to your organization. To demonstrate 'control' there would generally be some prescribe forms for you to fill in and return it to them for their information and records. Generally, you do keep copies of such forms for record purpose. If your system requires you to keep similar information, you may use this or if there are some differences, you may modify this to suit your use. In my opinion, these are part of contract (out sourced) requirements and not to be confused with external documents.