I had my records validated by my CPA, broker-dealer(s) and the B/D's clearing firm. B/D alone is not always accepted, unless they self-clear. Good luck.
I know a guy who was an options trader in Philadelphia. He said he and his group were all using their credit cards to lever up their strategy. Eventually they sold a portion to BNP Paribas and went from managing $100 M to $5 Billion over night. Recently all the partners cashed out for ~$30 MM a piece. Now they run a trading company, quant hedge fund and VC fund and have institutions banging down the door to get in. Using your credit card to lever up is probably a bad idea 90% of the time...but in this guy's case it worked. I'm not recommending it though....