That changed when Marcus learned how much of his rideshare income could be subject to income and self-employment taxes. “I looked at the number and thought, I’ve been robbed,” he joked.

The real problem wasn’t that someone had taken his money. Marcus had driven thousands of business miles but never maintained a consistent mileage log. He had also paid for parking, phone service, vehicle supplies and other work-related expenses without keeping organized records.

Some of those costs could potentially reduce taxable business income, but without documentation, determining and supporting eligible deductions became much harder.

Marcus left with a new plan: track mileage, save receipts, review his rideshare tax documents and set aside part of each week’s earnings for taxes.

The lesson: good tax planning starts long before the tax return is prepared.