Transfer funds from 501c4 to 501c3

I have two companies, both for the same non-profit organization.  We have an administrative company which is used for dues and administrative expenses and a service company with income from fundraisers and expenses to organizations and scholarships.  When the service company gets low in funds I transfer funds from the administrative company to the service company.  What type of accounts other than income and expense do I need for each company to track the transfer?