Signed service agreements and statements of work, recent invoices showing the volume providers handle, purchase-approval limits, and written instructions the applicant has given a vendor. Add a structure chart that places providers alongside employees so the delivery model is visible on one page.
Show the arrangement in operation
Contracts describe what was agreed; invoices, service reports, and correspondence show what happens. Where a provider has effectively acted as the operations team for years, that pattern is worth evidencing rather than summarising in a sentence. Note any agreement that has lapsed or been replaced by an informal understanding, because a reviewer comparing paperwork with practice will find it.
Identify who in the business can retrieve each item quickly. Take a sample rather than everything: one quarter of invoices, the two largest agreements, the approval limits as actually applied, and a dozen instructions the applicant sent to providers. A reviewer reads a sample, while a box of paper delays the reading and buries the good material.
Include the corporate documents establishing the relationship between the foreign entity and the United States entity, since the vendor picture is irrelevant if the qualifying relationship is not shown. Where a provider has been paid without a current agreement, prepare a short factual note explaining the arrangement rather than producing a contract dated after the payments. Identify one person in the business who can answer follow-up requests quickly, and give that person the file index.