The most expensive mistake restaurant owners make is not tracking food cost as a percentage of revenue. Most restaurants should run between 28% and 35% food cost depending on the concept. If you’re not calculating this weekly, you won’t catch waste, theft, or supplier price increases until they’ve already eaten your margin for months. This requires regular inventory counts and accurate cost of goods sold tracking in your accounting software.

Tip reporting is another area where restaurants consistently get it wrong. The IRS requires that all tips be reported, including cash tips. Employers are responsible for withholding payroll taxes on reported tips and paying the employer share of FICA on those amounts. Underreporting tips creates liability for the business, not just the employees. If the IRS audits and finds discrepancies, the restaurant owes back taxes, penalties, and interest.

Labor cost tracking matters almost as much as food cost. Your labor percentage should typically fall between 25% and 35% of revenue. Many restaurant owners look at total payroll but don’t break it down by front of house versus back of house, or by shift. Without that detail you can’t identify overstaffing on slow nights or understaffing that drives overtime costs up.

Commingling personal and business expenses is rampant in restaurants and bars, especially owner-operated ones. Buying groceries for home on the restaurant account or paying personal bills from the business checking account makes your books unreliable. It also makes tax preparation significantly more expensive because someone has to sort through every transaction to separate personal from business.

Not reconciling POS sales to bank deposits daily is a mistake that lets cash discrepancies go unnoticed. Cash-heavy businesses need tighter controls. If your POS says you sold $4,200 on Tuesday but only $3,900 hit the bank account, you need to know why immediately, not three months later when your bookkeeper finds it.

Falling behind on bookkeeping is probably the most common issue of all. Restaurant owners are busy running the floor, managing staff, and dealing with vendors. The books get pushed off until tax season, and then everything is a scramble. Monthly bookkeeping services keep your numbers current so you can actually use them to make decisions about menu pricing, staffing, and expansion.

Ignoring sales tax obligations creates problems that compound quickly. Tennessee has specific rules around food and beverage taxes at the state and local level. Filing late or miscalculating what you owe leads to penalties that add up fast.

Finally, many restaurant owners use a chart of accounts that doesn’t reflect how restaurants actually operate. Your financial statements should show you food cost, beverage cost, labor, occupancy, and other controllable expenses as distinct line items. A generic setup that lumps everything into broad categories won’t tell you where your money is going or where you’re losing it.