Seven Deductions Small Businesses Routinely Miss

Every filing season we review a stack of prior-year returns for new clients, and the same pattern appears: the deductions that were missed were never aggressive or obscure. They were ordinary business expenses that simply never got recorded.

Home office proportions are the most common. Owners who work three days a week from a spare room often claim nothing at all, because the calculation feels risky. It isn't — it's arithmetic, and it needs to be documented consistently rather than estimated in April.

Vehicle use is second. Without a contemporaneous log, a legitimate business proportion becomes unsupportable, so it gets dropped entirely. A logging app takes two minutes a week and preserves thousands of dollars a year.

Then come the small recurring items: professional dues, subscription software billed to a personal card, bank and merchant processing fees buried in gross deposits, interest on a business line of credit, training and certification costs, and the portion of a phone plan that is plainly business use.

The remedy is not a better preparer. It's a bookkeeping rhythm that captures these while they're still fresh. Deductions found in real time are documented; deductions reconstructed a year later are guesses, and guesses get abandoned.