Cost of Goods Sold vs. Supplies on Schedule C (2026): Where Your Materials, Inventory & Software Actually Go

Published: July 25, 2026 · Reading time: 9 min

TL;DR: Cost of goods sold (COGS) is the cost of inventory and direct materials that become the product you sell — and you deduct it when the product sells, not when you buy it. Supplies (Line 22) are the incidental items your business burns through to operate — deducted the year you buy them. The difference is all about timing: put inventory in supplies and you'll overstate this year's deduction; put operating supplies in COGS and you'll bury a deduction you could have taken now. Pick one line per cost, follow the economic reality, and stay consistent.

If you sell anything physical — handmade goods, resale items, printed products, food — the single most confused pair of lines on Schedule C is cost of goods sold and supplies. They sound interchangeable. They are not. One is timed to the sale, the other to the purchase, and getting them mixed up quietly distorts your taxable income in a way the IRS can spot. Here's how to tell them apart for good.

The one rule that settles most cases

Ask a single question about the cost:

Does this item become part of a product I resell, or is it just used up running the business?

• Becomes part of a product you sell → Cost of Goods Sold (Schedule C Part III, flowing to Line 4)
• Used up operating the business → Supplies (Schedule C Line 22)

The fabric in a dress you sell is COGS. The scissors you cut it with are supplies. The wood in a table you build is COGS. The sandpaper and shop-rag you go through are supplies. Once you frame every cost as "product ingredient" versus "operating consumable," 90% of the confusion disappears.

What actually belongs in Cost of Goods Sold

COGS lives in Part III of Schedule C (lines 33–42) and the total flows up to Line 4. It captures the direct cost of the goods you sold during the year:

• Inventory you bought for resale (Line 36 — purchases)
• Raw materials and parts that go into finished products
• Direct labor paid to make the product (Line 37)
• Certain factory/production supplies and overhead (Line 39) that are consumed in production

The defining feature of COGS is timing tied to the sale. You start with beginning inventory, add purchases and materials, subtract ending inventory, and what's left is the cost of what actually sold. That's why buying $8,000 of product in December that's still sitting on your shelf on December 31 produces zero current-year deduction — it's ending inventory, not COGS yet.

If you carry inventory, our deep dives on Schedule C Part III cost of goods sold and inventory valuation on lines 33–34 walk through the arithmetic line by line. Resellers specifically should read inventory, COGS, and receipts for resellers.

What belongs in Supplies (Line 22)

Line 22 is for the incidental, consumable items your business uses up in the ordinary course of operating — things that are not held for sale and not a direct component of a product:

• Office supplies (paper, pens, printer ink, shipping tape)
• Cleaning and shop supplies used generally, not per-product
• Small tools with a short useful life
• Packaging and shipping materials when you're not tracking them as part of product cost
• Software and app subscriptions used to run the business

The key: supplies are deducted in the year you buy and use them, full stop. There's no inventory calculation, no waiting for a sale. That immediate write-off is exactly why misclassifying inventory as supplies is tempting — and exactly why it's wrong. For the full picture of what else lands where, see our Schedule C deductions list and how to categorize expenses for Schedule C.

Side-by-side

The gray areas that trip people up

Packaging and shipping materials

Boxes, labels, and mailers are supplies (Line 22) for most small sellers. But if you're formally tracking product cost, packaging that's an integral part of the sold item can be pulled into COGS. Pick one method and stick with it — don't deduct the same box twice.

Software and SaaS

Your accounting app, design software, or storefront subscription is not COGS — it's an operating cost. Put recurring software on Line 22 (supplies/software) or Line 27a (other expenses). See Line 22 supplies and software for the distinction.

Tools and equipment

A $20 consumable tool is a supply. A $2,000 machine is a capital asset — depreciate it on Line 13, or expense it immediately with the de minimis safe harbor or Section 179. Neither belongs in COGS unless the tool is literally consumed to make one product.

Direct labor vs. contract labor

Wages paid to produce inventory go into COGS (Line 37). Payments to contractors for general business work (a bookkeeper, a marketer) go on other lines entirely, not COGS.

Why the timing difference matters for your tax bill

This isn't bookkeeping pedantry — it changes what you owe this year:

• Classify inventory as supplies → you deduct the full purchase now, overstating this year's expenses. When the products sell next year, you've got income with no matching cost. The IRS sees the mismatch, and it's a classic exam adjustment.
• Classify operating supplies as COGS → you delay a deduction you were entitled to take immediately, overpaying tax this year.

Because COGS reduces both your income tax and your self-employment tax on the profit, getting the number right matters twice. If you want to understand how that profit flows into SE tax, read self-employment tax explained.

A simple workflow to keep them straight

1. Tag every purchase at capture. When a receipt comes in, decide immediately: product ingredient (COGS) or operating consumable (supply). It's far easier in the moment than at year-end.
2. Keep inventory purchases in their own bucket. Don't let raw materials mingle with office supplies in your records.
3. Count ending inventory once a year. COGS is impossible to get right without knowing what's still on the shelf December 31.
4. Be consistent. Whatever method you pick for gray-area items, use it every year — consistency is a legitimate accounting principle and an audit defense.
5. Keep the receipts. COGS and supplies both need documentation; our guide to audit-proof business expenses covers what "adequate records" means.

An expense tracker that lets you tag each receipt to the right Schedule C line as it arrives turns this from a year-end nightmare into a two-second decision. That's the whole point of categorizing at capture instead of reconstructing in April.

Frequently Asked Questions

What is the difference between cost of goods sold and supplies on Schedule C?

COGS (Part III / Line 4) is the cost of inventory and direct materials that become the products you sell, deducted when the product sells. Supplies (Line 22) are incidental operating items, deducted the year you buy them. Ask whether the cost becomes part of a product you resell (COGS) or is used up running the business (supplies).

Do I have to use cost of goods sold if I sell products?

If inventory is a material income-producing factor, you generally must account for COGS with beginning and ending inventory. Small cash-method businesses under the $30 million gross-receipts threshold can treat inventory as non-incidental materials and supplies, still deducting the cost when the item sells.

Where do tools and software go on Schedule C?

Consumable tools and recurring software subscriptions go on Line 22 (or Line 27a for software). Expensive, long-lived equipment is a capital asset — depreciate on Line 13 or expense with the de minimis safe harbor or Section 179. None of these are COGS unless consumed to make a specific product.

Can the same expense be both COGS and supplies?

No. Each cost belongs in exactly one place, and double-counting is an audit trigger. Material that becomes part of a sold product is COGS; general operating items are supplies. Choose one line per cost and be consistent.

Does it matter for my taxes which line I use?

Yes — because of timing. Supplies deduct immediately; COGS deducts only when the product sells. Misclassifying inventory as supplies overstates this year's deduction and understates next year's, a mismatch that surfaces in audits.

Authoritative References

• IRS — Schedule C (Form 1040) Instructions
• IRS Publication 334 — Tax Guide for Small Business
• IRS — Inventories (Publication 538, Accounting Periods and Methods)
• IRS — About Schedule C (Form 1040)

Tag Each Receipt to the Right Line — Automatically

The fastest way to stop mixing up COGS and supplies is to decide the moment a receipt lands, not next April. CentSense scans each receipt, pulls the amount and vendor, and lets you tag it to the exact Schedule C line — supplies, materials, software, or COGS — so your records are sorted as you go and your CSV export is CPA-ready. Start free with 10 AI scans a month, no credit card; the Solo plan ($5/month) adds unlimited scanning and mileage tracking.

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This article is educational and not tax advice. Consult a qualified tax professional about your specific situation.