I've been doing consulting past 10 years or so under my own llc. Put the major end clients I was with as it was full time engagements 12mo+ including some international on resume. Is this a deal killer for a cisco background check if they can't verify employment from resume? The work was legit but HR would have no records of me at any of the companies and alot didn't even send 1099's as they just paid monthly invoices.
Provide copies of contracts, invoices, and checks with the financial details redacted.
Just provide references if they really want to confirm.