NWC28 wrote:(Also I'm aware that this is a touchy subject about the declaration of tips. I can assure you that the way I declare is completely legal where I live. There is a minimum for the declarations of tips which I meet every pay period.)
No, it's not. Federal law requires the declaration of all income from tips, if the income exceeds $20 a month. That's black letter law, there's nothing 'touchy' about it. Failing to report all the income opens you up to all sorts of liability for not paying taxes. Your employer may tell you otherwise, but that's because having you under report your tips saves them having to pay payroll taxes on the unreported amount.
Having said that, AMEX will not take income that you're making under the table into account. They're very touchy about being involved in tax fraud and money laundering. If you say you make X, and they FR you and see the number is X/2, they'll shut you down. If you say you make X/2, and they FR you, and decide your spending isn't consistent with that income, they'll shut you down. The odds of Amex noticing are about the same as the IRS noticing, so do what you will.