I have always thought that the seller or the service provider would be the one to give out the invoice just like a regular store?
sorry i still dont understand who is suppose to give out the invoice? is it me or my partner? my partner receives monies from affiliate company. and he pays 50% for advertising cost, am i suppose to give him invoice or does he give me an invoice?
Receipts, cancelled checks, bank statements. Make sure each expense(payment to him) can be tracked in all three ways and you're fine. Keep your records in case you're ever audited.
http://www.blackhatworld.com/blackhat-seo/business-tax-advice/244957-document-nearly-any-business-legal-situation.html#post2183726