Two Lists Every Year: What Gets Claimed Wrongly and What Gets Left Behind

Two lists turn up in every conversation about business expenses, and they are very nearly the same two lists every year. One holds the things people confidently claim that do not qualify, and the other holds the things that plainly do qualify and never get claimed, usually because nobody ever mentioned them. The underlying test for both is a single sentence, being ordinary and necessary for the business with the personal portion carved out, and almost every item below is an application of that one sentence rather than a separate rule.

The Commute, Which Is the Most Common Error

Driving from home to your regular place of work is personal rather than business, regardless of whether you are self employed and regardless of whose vehicle it is. Travel between work locations during the day is business, and travel to a temporary work location outside your usual area is business. That distinction accounts for more incorrect mileage than everything else combined, largely because it feels wrong to people who genuinely are working from the moment they get in the truck.

One thing rescues a great deal of it for trades. Where your home qualifies as your principal place of business, trips from there to job sites are business miles rather than commuting, because you are traveling between two work locations rather than to work. That single fact changes the mileage picture substantially for a contractor doing administration from a qualifying room at home, which makes establishing the home office properly worth more than the home office deduction itself is.

Clothing and Meals, Where Intent Is Not the Test

The clothing test is not whether you bought it for work but whether it is suitable for ordinary wear away from work. A suit fails even if it only ever gets worn to see clients, and ordinary boots and jeans fail even on a job site. What passes is genuine protective equipment, uniforms carrying a company logo that would be odd to wear elsewhere, and specialized gear with no everyday use, and the cleaning costs for qualifying items are deductible too, which people miss regularly.

Meals sit next to that with the same shape. Your own lunch while working is personal and does not become deductible because the day was busy. What qualifies, at the limited percentage the rules allow, is a meal with a business purpose, meaning a client, a supplier, a candidate or a partner, where business was actually discussed. The record required is the amount, the date, the place, who was there and what the purpose was, and the last two are the ones nobody writes down, although a single line typed into a phone at the table satisfies the whole requirement.

The Whole Phone Bill and the Whole Internet Connection

Claiming a hundred percent of a phone that is used personally as well as for business is a routine error rather than an aggressive position. The deductible portion is the business share and you need a basis for the split, which the clean answer removes entirely: a second line used only for business, which is inexpensive and eliminates the allocation question. Failing that, a reasonable percentage documented once, based on actual usage rather than a round number chosen because it sounded defensible. Home internet gets exactly the same analysis, being a share, based on business use, written down at the time it was decided.

The Ones Left on the Table

Now the other direction, where the money usually turns out to be larger. Mileage heads the list because there is no log, which makes it the single biggest missed deduction for service businesses, with people driving thousands of business miles and claiming a fraction because the rest cannot be substantiated. An app that records trips automatically converts that from a guess into a number. Startup costs incurred before the business opened come next, covering market research, professional fees, initial supplies and travel to look at locations, and they are frequently forgotten entirely because they predate the bookkeeping that would have caught them.

Then the larger structural ones. Self employed health insurance premiums, which for many are deductible in arriving at adjusted gross income rather than as a business expense, subject to conditions, and which are routinely missed by people preparing their own returns. Retirement contributions, where self employed plans allow amounts well above an ordinary individual account and the deadlines for establishing and funding them differ by plan type, making this the largest single lever most profitable sole operators have and one many never examine. Half of self employment tax, handled automatically by software and sometimes missed on a manually prepared return.

And then the quiet ones. Bank and payment processing fees, small individually, meaningful annually, invisible because they never arrive as a separate transaction. Actual vehicle costs where that method beats the standard mileage rate, which requires more records and can be substantially better for a heavily used or expensive vehicle, with consequences for later years that make it worth deciding deliberately in year one. Bad debts where you use accrual accounting and previously recorded income you never collected. And continuing education that maintains or improves skills in your existing trade, noting that education qualifying you for a new trade does not count, which is the line people trip over.

The Gray Areas, Handled Honestly

Some things are genuinely mixed and the answer is allocation rather than a yes or a no: a vehicle used both ways, a laptop the family also uses, a trip combining a conference with three days of vacation, a room that is mostly an office. What holds up is deciding the split on a defensible basis, writing down the reasoning and the date at the moment you decide it, and then applying it consistently year after year.

What does not hold up is a round number with no explanation behind it, or a split that shifts each year in whichever direction happens to be convenient. Whether an expense was legitimate is rarely the question that causes trouble. Whether it was substantiated usually is, which is why the Internal Revenue Service sets out what a record must contain for travel, meals and vehicle use in far more detail than it spends on what qualifies in the first place.

The Structural Question That Outranks Both Lists

Categorize transactions weekly and write the business purpose at the same time, because doing it weekly means you still remember and the note is the entire difference between a bank line and a record. Then once a year before filing, read your own category list top to bottom and ask two things of each entry: could I explain this to somebody skeptical, and is there a category here that ought to exist and does not. The first question catches the wrongly claimed items and the second catches the ones being left behind, which are usually worth more.

Every item on both lists is worth a few hundred or a few thousand dollars. The decision about how you are taxed is worth more than most of them combined. It is also a different kind of question: whether to operate through an entity, whether an election makes sense at your level of profit, whether a retirement plan should be established this year, whether the accounting method you started with still fits. Owners substitute one for the other constantly, spending six hours hunting a missed deduction and never spending one hour on the structure, because a deduction feels concrete while a structure feels abstract. Do the weekly categorizing, which makes everything else possible, and then book the hour.