If you receive cash income and need to provide proof of income for renting an apartment, consider alternative documentation such as providing a letter from your employer detailing your income, submitting copies of your tax returns to show your annual earnings, offering to pay a larger security deposit or several months' rent in advance to demonstrate financial stability, presenting invoices or receipts if you're self-employed to verify income, or maintaining a detailed record of your cash income and expenses. These alternatives can serve as evidence of your ability to meet rental obligations without traditional bank statements.