The answer is straightforward. If you’re a sole proprietor, no law says you must have a separate bank account. But you should open one anyway, and the sooner the better.

When business income and expenses run through your personal checking account, everything gets tangled together. Groceries sit next to material purchases. Your rent payment shows up between customer deposits. Come tax time, someone has to sort through every transaction and decide which ones were business and which were personal. That process takes hours and you will inevitably miss things.

Those missed things cost you money. The $180 in supplies from Home Depot, the fuel for driving to a job site, the tool replacement you grabbed on the way home. When business expenses are scattered across hundreds of personal transactions, deductions fall through the cracks. Over twelve months, that adds up to real tax savings you’re leaving behind.

If you’ve set up an LLC or corporation for your side business, separating accounts becomes even more important. Mixing personal and business funds can undermine the liability protection your LLC is supposed to provide. Courts call it “piercing the corporate veil,” and it means your personal assets could be exposed in a lawsuit or judgment. The entire purpose of the entity structure disappears if your finances aren’t separated.

A dedicated business account also makes bookkeeping for trades businesses far simpler. Bank feeds connect directly to QuickBooks, and every transaction in that account is business by default. No sorting, no guessing, no forgotten expenses. Your books stay clean with minimal effort, and your tax preparer gets exactly what they need without chasing you for explanations.

Setting up a business checking account takes about an hour. Many banks offer free or low-cost options for smaller operations. Bring your EIN or Social Security number, your ID, and any formation documents if you have an LLC. Start running every business transaction through it from that point forward.

If you’ve already been mixing personal and business transactions for a while, don’t stress about it. Catch-up bookkeeping can sort through the history and get everything organized so you have clean records going forward. The important thing is to make the switch now rather than letting another year of mixed transactions pile up.