Ecommerce tax deductions: what qualifies, and the ones most sellers get wrong

If you are pulling together deductions for an online business, the general rule is broader than people expect and the specific rules are narrower. Almost any spending that is ordinary and necessary for your business is deductible, so the list of categories is long and not very interesting.

What matters are the three that behave differently from how sellers assume. Inventory is not deductible when you buy it, only when it sells. Your 1099-K reports a figure larger than your actual revenue, and the gap has to be closed with deductions rather than ignored. And the home office deduction works differently depending on whether you operate as a sole proprietor or through a company.

Here is the test that governs everything, the three that trip people up, and what is not a deduction at all.

Ordinary and necessary is one test, not two categories

Guidance often splits expenses into ordinary ones and necessary ones, as though advertising is one type and insurance is another. That is a misreading. Every deductible business expense has to be both.

Ordinary means common and accepted in your line of business. Necessary means helpful and appropriate for it, which is a lower bar than indispensable. An ad spend, a Shopify subscription, packaging, a photography backdrop, and an SSL certificate all pass both parts without difficulty.

The test bites at the edges rather than the center. A mixed-use purchase has to be split between business and personal, an expense that is lavish relative to your operation invites questions, and anything with a personal flavor needs a business purpose you can articulate. For the ordinary run of ecommerce spending, the test is not the constraint. Documentation is.

Inventory is not deductible when you buy it

This is the single most common ecommerce tax mistake and it usually surfaces as a December surprise.

Buying $60,000 of stock does not create a $60,000 deduction. Inventory sits on your balance sheet as an asset until it sells, at which point its cost moves into cost of goods sold and reduces your taxable income. Cost of goods sold is beginning inventory plus purchases minus ending inventory, so a large purchase that has not sold by year end has no effect on your tax bill at all.

Cost of goods sold includes more than the product cost. Inbound freight, import duties, and the direct cost of getting inventory ready for sale generally go in. Outbound shipping to your customer does not; that is a separate operating expense.

There is an exception worth knowing. Small business taxpayers under a gross receipts threshold may elect a simplified treatment that allows inventory to be handled as materials and supplies or to follow the method used in their books, rather than applying the full inventory accounting rules. The threshold is indexed and the election has conditions, but for a seller of moderate size it can substantially simplify the year end.

Your 1099-K overstates your revenue

Payment platforms and marketplaces report gross processed volume. That figure includes the platform's fees, payment processing fees, refunds, chargebacks, and sales tax collected. Your actual revenue is smaller, sometimes by a wide margin.

The reporting threshold for these forms has moved repeatedly in recent years and settled back toward its long-standing level, so whether you receive one depends on the current rule and on your state, several of which set lower thresholds than the federal one.

Either way the obligation is the same. You report the gross figure and then deduct the components that were never yours: merchant fees, marketplace commissions, refunds, and shipping charged to you. Sales tax you collected is not revenue at all. A seller who reports only net deposits creates a mismatch against the form the IRS already has, which is the kind of discrepancy that generates a notice.

Closing that gap requires books that categorize platform payouts into their components rather than recording the deposit as a single line. We handle monthly bookkeeping and file the 1099 and W series, which is the arrangement where the reconciliation exists before the return needs it rather than being reconstructed afterward.

The home office deduction depends on your entity

Most guidance describes this as available to online sellers generally. It is not, and the difference is structural.

Sole proprietors and single-member LLCs. You can claim it directly. The space has to be used exclusively and regularly for business and be your principal place of business. The simplified method gives a flat rate per square foot up to a capped area. The regular method deducts a business-use percentage of rent or mortgage interest, utilities, insurance, and repairs, and can include depreciation for homeowners. The deduction generally cannot create a loss.

Corporations, including S corporations. The company cannot deduct your home, and you cannot deduct it personally, because unreimbursed employee expenses are not deductible. The route that works is an accountable plan: the company reimburses you for the business-use portion under a written arrangement with substantiation, deducts the reimbursement, and the payment is not taxable to you.

Owners of incorporated ecommerce businesses who claim a home office deduction on their personal return are making a claim the current rules do not support. The accountable plan achieves the same economics through a different mechanism.

Repairs are deductible, improvements are not

Fixing something is an expense. Making it better, longer-lived, or adapted to a new use is a capital improvement that gets depreciated rather than deducted. There is no partial deduction category between the two.

Three safe harbors soften this in practice. A de minimis election lets you expense items below a per-item threshold outright, provided you have a written capitalization policy in place before the tax year starts. A routine maintenance safe harbor covers recurring upkeep you expect to perform more than once over a set period. A small taxpayer safe harbor covers modest amounts spent on a building for businesses below a gross receipts threshold.

For most ecommerce sellers the de minimis election does nearly all the work, and the main cost of not having the written policy is that equipment purchases end up on a depreciation schedule unnecessarily.

Pass-through owners have a deduction that is not an expense

If your business is a sole proprietorship, partnership, LLC, or S corporation, you may be able to deduct a percentage of qualified business income on your personal return. It is not an expense and it does not require spending anything.

It phases out above income thresholds, with additional tests that depend on wages paid and property held once you pass them. Ecommerce businesses generally qualify by type of trade, unlike certain service businesses that face restrictions. Because it operates at the owner level rather than the business level, it is frequently missed by sellers who focus only on business expenses.

What is not a deduction

Sales tax you collected. It was never your money. It is a liability you hold and remit, so it belongs in neither revenue nor expenses.

Inventory you have not sold. Covered above, and worth repeating because it is the expensive one.

Owner draws. Money you take out of a sole proprietorship or an LLC taxed as one is not a wage and not deductible. Salary paid to a shareholder-employee of a corporation is, within reason.

The personal portion of anything. Phone, internet, vehicle, and home costs are deductible only to the extent of business use, and the split needs a basis you can explain.

Clothing. Ordinary clothes are not deductible even if you only wear them for work or for product photography.

The bottom line

The deduction list is not where the money is. Almost everything you spend running an online store qualifies, so getting the total right depends on categorized books rather than on discovering an unusual category. Where sellers actually lose is timing and reconciliation: inventory deducted a year early, a 1099-K reported against net deposits, a home office claimed on the wrong return. Fix those three and set a written capitalization policy before the year starts, and the rest of the return is mostly a mapping exercise.

Frequently asked questions

Can I deduct inventory I bought but have not sold?

No. Inventory is an asset until it sells, at which point its cost becomes part of cost of goods sold. Buying stock in December does not reduce that year's taxable income unless it sells by year end. Small business taxpayers under a gross receipts threshold may be able to elect a simplified treatment that changes this.

Why is my 1099-K higher than my actual sales?

Because it reports gross processed volume, including platform and payment fees, refunds, chargebacks, and any sales tax collected. You report the gross figure and deduct the components that were never revenue. Reporting only your net deposits creates a mismatch with the form the IRS already holds.

Can my LLC or corporation claim a home office deduction?

A single-member LLC taxed as a sole proprietorship can claim it directly. A corporation cannot, and its owner cannot claim it personally either, because unreimbursed employee expenses are not deductible. The working route for a corporation is an accountable plan reimbursement for the business-use portion.

Is the sales tax I collect a deductible expense?

No, and it is not revenue either. Sales tax collected is money you hold on behalf of a state and remit to it. It should not appear in either side of your income statement, though it will be included in the gross figure your payment platform reports.

Can I deduct costs incurred before I made any sales?

Startup costs are treated separately from ordinary operating expenses. A limited amount can be deducted in the first year the business is active, with a phase-out above a spending threshold, and the remainder is amortized over a fixed period. The business has to actually begin operating for any of it to be claimed.

What mileage rate can I use for business driving?

The standard mileage rate is set annually and changes most years, so use the rate published for the tax year you are filing rather than a figure from older guidance. Tolls and parking for business trips are deductible separately from the mileage rate.