Income on a statement is observed cash. Not salary slips. Not invoices. Deposits that repeated.
Step one: list all credits by month. Remove transfers between own accounts. Remove refunds and reversals.
Step two: group what remains by payer pattern. Same descriptor, similar timing. Salary repeats monthly. Gig repeats weekly.
Step three: take the median across months. Median beats average. One spike month does not inflate it.
Step four: check stability. Steady credits score high. Gaps and late deposits score low. Lenders trust steady over tall.