Do you need a separate business bank account?

For an LLC or corporation this is close to mandatory in practice even where no statute compels it. Commingling personal and business money is the single most cited factor when courts pierce the corporate veil and hold owners personally liable for business debts, because the argument that the company is a separate entity collapses when its finances are indistinguishable from yours. Paying for groceries from the business account and a client invoice from your personal one is the exact pattern that gets used against you.

Even a sole proprietor with no entity benefits substantially. A dedicated account means the year-end bookkeeping is a matter of categorizing one statement rather than reconstructing which of two hundred personal transactions were deductible. It makes an audit far less painful, because the IRS examining a commingled account can question every deposit as potential unreported income and the burden of proving otherwise is yours. It also makes the business legible to anyone evaluating it, including lenders and buyers.

Practical guidance. Business checking accounts vary widely in fees, and many online banks and credit unions offer accounts with no monthly fee and no minimum balance, so paying for one is usually unnecessary at small scale. Most banks require an EIN and formation documents to open a business account for an entity, while a sole proprietor may be able to use a DBA registration. Add a business credit or debit card on the same account so expenses stay separated at the point of purchase rather than through later reimbursement, and pay yourself by a deliberate transfer, called an owner's draw, rather than spending from the business account directly.