If your business makes or sells physical products, a big chunk of your tax return depends on one number, and that number comes from Form 1125-A.
Form 1125-A is the IRS form used to calculate and report cost of goods sold. It is the worksheet where a corporation adds up what its inventory actually cost, subtracts what is left at year end, and lands on the figure that flows onto the main return. Get it right and your gross profit is accurate. Get the inventory numbers wrong and every figure below them on the return is wrong too. This guide covers what you need to know about IRS Form 1125-A: who must file it, how to complete it line by line, and the common pitfalls that trip filers up.
Think of this guide to Form 1125-A as the plain-English version, because none of it is as complicated as the form first looks.
Once you understand the simple math behind cost of goods sold, the boxes on the page fall into place quickly.
Form 1125-A is used to figure and report the deduction for cost of goods sold.
It is what you spent producing or purchasing goods that were sold during the tax year. Subtract it from revenue and you get gross profit, which then drives your taxable income. Because that one number moves so much, the Internal Revenue Service wants it calculated on a standard schedule rather than guessed at, and the Form 1125-A Cost of Goods Sold schedule is exactly that. The amount reported on the form is what lets you deduct the cost of those goods against revenue. You complete and attach Form 1125-A to report your cost of goods, and that total carries to the cost line on your main tax return.
This is purely about goods, not services.
If you sell products, raw materials, or finished goods, this form is where you report the cost of those items. If you sell only your time or expertise, you almost certainly do not touch it.
Filers of Form 1120, 1120-C, 1120-F, 1120-S, or 1065 complete and attach this form if they report a deduction for cost of inventory.
In plain terms, corporations, S corporations, partnerships, and multi-member LLCs that carry inventory report their cost of goods here. If your business produces or buys goods for resale and tracks inventory, you need to file the form with your return, whether that return is Form 1065 or Form 1120-S. The trigger is inventory, not entity type. A manufacturer, a wholesaler, and an online retailer all need it, while a consulting firm or a law practice with no inventory does not.
Two groups are often confused here, so it helps to draw the line clearly.
Service businesses with no goods skip it entirely, since they have nothing to report here. Sole proprietors and single-member LLCs also skip it, but for a different reason: they report COGS on Schedule C, Part III, instead. If you file a single-member LLC return, your COGS lives on Schedule C, and the 1125-A form is not part of your filing.
The form is built around one formula, and every line feeds it.
Cost of goods available, minus what is left at year end, gives you the figure. Here is how the lines stack up.
That final figure does not stay on the form. Line 8 flows to the cost line on your return, where it is reported on Form 1120, page 1, line 2, or the matching line on your 1120-S or 1065. One quirk worth flagging: a 1120-F filer routes line 8 to Section II, line 2 rather than page 1.
After the math, the form asks how you value your inventory, and those answers live on line 9.
You check the method you use to value closing inventory: cost, lower of cost or market, or another approved method. Most small businesses use the cost method of accounting for inventory. If you use LIFO, last in first out, and you adopted it this tax year for any goods, you check the LIFO box and attach Form 970 to elect it. Line 9 also asks whether 263A applies and whether there was a change in determining quantities, cost, or valuations between opening and closing inventory, which ties to your inventory accounting method. A change there means checking yes and attaching an explanation, because the IRS wants your inventory method applied consistently from year to year.
The method you pick genuinely changes your numbers.
FIFO, LIFO, and weighted average can each produce a different cost of goods sold from the very same shelf of stock, which is why the choice matters and why switching is not casual. We cover the trade-offs in depth in our guide to inventory valuation methods, so this piece stays focused on the form itself.
Line 4 is where the UNICAP rules show up, and this is the part most filers get wrong.
UNICAP, the rule under section 263A, requires certain businesses to capitalize indirect costs into inventory rather than writing them off right away. Think warehousing, handling, and purchasing support costs tied to your goods. When these inventory and cost capitalization rules apply, those amounts go on line 4 and stay in inventory until the related goods are sold.
Here is the relief most small businesses miss.
If your average annual gross receipts over the prior three years stay at or under the threshold, which is $31 million for tax year 2025, you are exempt from UNICAP entirely. That means line 4 is zero and you skip the extra math. Plenty of qualifying businesses check the 263A box out of habit and drag themselves into a calculation they do not owe, so it pays to run the gross receipts test before you answer. The IRS inventory and cost capitalization expectations are real, but the small business exception is just as real.
A handful of mistakes account for most of the rework on this form.
The biggest is sloppy ending inventory, since line 7 directly sets the number you can claim, and an inflated count quietly inflates your taxable income. Right behind it is a beginning inventory that does not match last year's ending number, which the IRS notices immediately. Filers also forget to attach Form 970 when they adopt LIFO, answer the 263A question wrong, or carry line 8 to the wrong line on the parent return. None of these are hard to avoid once you know to look for them, and clean inventory records prevent almost all of them.
Consistency is the theme running through every pitfall.
Use the same inventory method each year, compute your beginning and ending inventory consistently, tie this year's opening figure to last year's close, and keep records that show how you valued everything.
You never file this form on its own.
You complete and attach it to your business return, and it rides along with that return on the same deadline. For calendar-year pass-through entities that is March 15, and for C corporations it is the 15th day of the fourth month after year end. If you need more time, an extension on the parent return covers it too. The point is simple: fill out the form, attach it, and file IRS Form 1125-A with the return it belongs to.
This is steady, detail-heavy work that rewards good records.
At Madras Accountancy, we help U.S. CPA firms prepare business returns where COGS is in play, reconciling inventory, completing the form, and coordinating the section 263A and valuation answers so the tax return is accurate and the gross profit holds up. For firms running high volumes of inventory-heavy returns, that is exactly the kind of work an offshore team takes off your plate.
What is Form 1125-A used for? Form 1125-A is used to figure and report cost of goods sold. Corporations, S corporations, and pass-through entities that carry inventory complete it to total their inventory costs, subtract ending inventory, and reach the figure that carries to the main business tax return.
Who must file Form 1125-A? Corporate and partnership filers must file it if they carry inventory and report it. In practice, that means corporations, partnerships, and multi-member LLCs with goods. Service businesses with none do not file it.
Do sole proprietors file Form 1125-A? No. Sole proprietors and single-member LLCs report cost of goods sold on Schedule C, Part III, not on this form. The 1125-A form is for corporations, S corporations, and pass-throughs that file business returns, not Schedule C.
How do you calculate cost of goods sold on Form 1125-A? Add beginning inventory, purchases, labor, additional section 263A costs, and other costs to get your cost of goods available for sale on line 6. Then subtract ending inventory on line 7. The result on line 8 is your cost of goods sold, which carries to your return.
What are additional section 263A costs on Line 4? These are indirect costs, such as warehousing and handling, that UNICAP requires you to capitalize into inventory. They sit on line 4 until the related goods are sold. Small businesses under the gross receipts test are exempt and enter zero.
Do I need to attach Form 970 to Form 1125-A? You attach Form 970 if you adopted the LIFO inventory method this tax year. It is the election to use LIFO. If you already use LIFO from a prior year or use another method like cost, you do not attach Form 970 again.
Where does the COGS from Form 1125-A go on my return? The amount on line 8 carries to the cost line on your main return, which is page 1, line 2 of Form 1120 or the matching line on your 1120-S or 1065. A 1120-F filer instead reports it on Section II, line 2.
Is Form 1125-A filed separately from my tax return? No. You complete and attach the form to your business return and file them together by the return's due date. It has no separate deadline, so if you extend the parent return, the form is covered. A tax professional can confirm the right method and 263A answers for your situation.
%2075-100%20(2).png)
An 83(b) election lets a startup founder pay tax on restricted stock at grant, not vesting. Learn how it works and why you must timely file one.
%2075-100%20(4).png)
How the mega backdoor Roth works in 2026: after-tax 401(k) dollars converted to a Roth IRA, so high earners build tax-free retirement savings.
%2075-100%20(7).png)
Form 9465 is the IRS installment agreement request taxpayers file to request a monthly installment plan when they cannot pay in full.
