If your husband works a traditional job, he could be split-depositing his paycheck. He might deposit a set amount into your joint account and deposit part of his regular paycheck, overtime, or bonuses into a separate account in his name only. When I worked in HR years ago, there was a male employee who asked me to deposit his quarterly profit-sharing check into a separate account from his regular paycheck, so his wife wouldn’t know about it.
If separation or divorce is looming, your husband might defer a bonus, raise, or promotion. If he knows he’s up for an increase in income, your husband might ask his boss to wait until your divorce is final to give him a promotion so your child support or maintenance is based on his current lower salary.
Business owning husbands have more places to hide income. If your husband owns his own business or professional practice, there are many opportunities to artificially lower income. He could receive client payments in cash, keeping the income “off the books.” Your husband might purposely overpay vendors or the IRS, knowing he’ll get refunds after the divorce is final. He could also delay the receipt of orders or customer payments. If your husband is a business owner and his once successful venture started having money problems right around the time of divorce, it might be wise to retain a forensic accountant.