Amazon Aging Inventory Accounting: Fees, Write-Downs, Books

Aged FBA inventory costs you twice. Amazon charges a surcharge on units that sit too long, and your books can quietly misstate profit if you record that surcharge, or the stock itself, in the wrong place. The short version: carry unsold units as inventory at cost, book storage and aged inventory surcharges as operating expenses (not COGS), and write stock down only when it has genuinely lost value or left your hands. The rest of this guide shows how, with the current fee tiers and a worked example.

TL;DR

• Amazon’s aged inventory surcharge starts at 181 days and climbs sharply after 270 days, so the date a unit lands matters as much as its cost.
• Record the surcharge as an operating expense. Putting it in COGS inflates cost of goods and hides the true margin of each product.
• Unsold units stay on the balance sheet at cost until they are sold, disposed of, or valued lower under a method you apply consistently.
• Inventory turnover tells you early whether cash is trapped: below 4 turns a year is a warning sign for most FBA sellers.
• Reconcile Amazon’s inventory and settlement data to your ledger every month, or aging problems stay invisible until the fee shows up.

Table of Contents

• What counts as aged inventory on Amazon
• How to account for aged inventory: the core rules
• A worked example: one slow SKU
• Write-downs, disposals and write-offs
• Keep settlements from distorting your numbers
• Aging inventory reporting: what to track every month
• How to manage aging inventory before it gets expensive
• Our perspective: aging inventory is a data problem first
• Where BeanHawk fits
• FAQ
• Sources

What counts as aged inventory on Amazon

Aged inventory is stock that has sat in Amazon’s fulfillment centers beyond a set number of days. Amazon’s surcharge applies to units stored 181 days or longer, and the fee is charged per cubic foot, not per unit, so bulky slow movers hurt most. Our glossary entry on the aged inventory surcharge covers the definition in short form.

According to Amazon’s own seller forum guidance on the fee structure effective January 16, 2026, the per-cubic-foot tiers run like this:

Notice the cliff at day 271. The fee jumps from $1.50 to $5.45 per cubic foot, more than triple. If you plan to clear stock, do it before that date. Amazon’s rates change, so check your own account and the current FBA fee guide before you set a deadline.

Aged units are not the only inventory cost. Monthly storage fees apply to everything you hold, and they vary seasonally, with higher rates in the holiday months, according to Amazon’s FBA fees guide.

How to account for aged inventory: the core rules

Three principles cover almost every situation.

1. Unsold units are an asset, not an expense

Inventory you paid for and have not sold sits on your balance sheet. It becomes cost of goods sold only when the unit sells. The IRS requires that, where inventory is needed to determine income, you value it at the beginning and end of each tax year to calculate COGS; see IRS Publication 538 for the accounting rules and the small business exception. This is why a pallet that has aged for 300 days is still an asset in your books, even though it is costing you money every month.

Your asset value should include landed cost: purchase price plus freight, duties and prep that you paid to get the unit ready to sell. If you only record the supplier invoice, your margin looks better than it is. Our guide on tracking inventory for an FBA business walks through the data you need per SKU.

2. Fees that come from aging are operating expenses

Storage fees and the aged inventory surcharge are costs of holding stock, not costs of the stock. E-commerce accountants at Ledger Labs point out that these fees are operating expenses, not part of COGS, and that misclassifying them inflates cost of goods and distorts gross margin. Give each fee type its own expense account, such as “FBA storage fees” and “FBA aged inventory surcharge”. When the surcharge line grows, you will see it immediately.

3. Valuation must be consistent

The IRS describes common methods such as cost, and lower of cost or market, where you compare the current market bid price on the inventory date with cost and use the lower figure. Whatever you pick must be applied consistently year over year, and changing methods generally means filing Form 3115. That is a conversation for your CPA, not a mid-year spreadsheet tweak.

A worked example: one slow SKU

Say you bought 1,000 units of a kitchen organizer at $6.00 each, plus $1.20 per unit in freight and prep. Landed cost is $7.20 per unit, so $7,200 goes on the balance sheet as inventory.

Over six months you sell 600 units. COGS is 600 x $7.20 = $4,320. The remaining 400 units are still an asset worth $2,880.

Now suppose those 400 units occupy 20 cubic feet and enter the 271-300 day tier. At $5.45 per cubic foot, the monthly surcharge is $109. That $109 is an operating expense. It does not change the $2,880 asset value, but it eats the profit you expected from selling those units.

This is the real decision the books should support: compare what the remaining units can still earn against what holding them costs. If each unit nets $4 after fees at normal price, 400 units are worth about $1,600 of profit. If the surcharge and storage will run $109 a month and the units sell at 20 a month, you are paying roughly $5 per unit sold in holding costs and will still carry the aging problem for 20 months. A discount or removal is likely better than waiting.

Write-downs, disposals and write-offs

Sellers searching for inventory write-offs usually mix up three different events. Keep them apart.

Two cautions. First, do not write off units just because they are old. Documented evidence matters: sales history, market prices, disposal confirmation. One CPA-oriented guide advises that monthly comparison of your books to Amazon’s FBA inventory reports is what lets you spot damaged, lost or miscounted units, and that excessive write-offs can draw scrutiny. Second, talk to a CPA or enrolled agent before you take a large write-down. The tax treatment depends on your accounting method and entity, and only they can see your full return.

Check for reimbursement before you write off

A lot of “aged” or “missing” stock is really stock Amazon lost or damaged. Writing it off as your loss gives away money Amazon may owe you. Warehouse lost and damaged claims generally have to be filed within 60 days of the loss report, customer return claims have windows of 60 to 120 days after the refund, and removal order claims 15 to 75 days, according to this 2026 summary of Amazon’s reimbursement policy. The source is aimed at EU sellers, so confirm the windows for your marketplace in Seller Central. Miss a window and the claim is denied even if the loss is real.

Our reimbursement glossary page explains how the claims work.

Keep settlements from distorting your numbers

Aging inventory accounting fails most often at the settlement step. An Amazon settlement bundles sales, refunds, fees and reimbursements into one net deposit. If your bookkeeper records only the deposit, gross revenue is understated and COGS is distorted, as Ledger Labs explains. Accurate books map each settlement line to the right account, so the aged inventory surcharge lands in its expense account and reimbursements land where you can see them.

The same discipline helps at tax time. The 1099-K you receive from Amazon reports gross payments, not profit, and it ignores your COGS and expenses. A CPA firm that works with FBA sellers recommends reconciling it against your settlement ledgers and order records. That reconciliation only works if your inventory and fee records are already clean.

If you use QuickBooks, start with our guide to Amazon cost of goods in QuickBooks, and for count mismatches see Amazon inventory reconciliation. The broader process is in our FBA bookkeeping guide.

Aging inventory reporting: what to track every month

You do not need a complex dashboard. A monthly review with these columns catches most problems 60 to 90 days before they cost money.

1. Units and landed cost by SKU and age bucket (0-90, 91-180, 181-270, 271+ days).
2. Projected surcharge for the next 60 days. Amazon’s FBA Inventory tool lets you filter by time in the fulfillment center, and its forum guidance says to identify ASINs that will cross 181 days by the next cleanup date. Amazon also launched a FBA Inventory Age & Excess Analytics page with trends and key metrics.
3. Days of supply at the current sales rate, compared with your supplier lead time.
4. Turnover ratio (COGS divided by average inventory value).
5. Fees paid versus fees avoided, so you can see whether your actions are working.

Reading turnover honestly

FBA sellers often aim for 6 to 12 turns a year, and below 4 suggests cash is stuck in slow or aged stock. But category matters: fast consumables can reach 10 to 15 turns, while durable goods are often healthy at 2 to 4. Set your target from lead time, margin and what it costs to hold stock, not from a universal number.

Your IPI score ties in here too. Amazon calculates it partly from sell-through and aged inventory, and it can determine whether you face storage restrictions, per Threecolts’ turnover guide. See our explainer on IPI.

How to manage aging inventory before it gets expensive

Accounting records the damage. These steps prevent it.

• Act at day 120 to 150, not 181. Lower the price, run a promotion, or bundle slow units with a fast mover. Bundles need their own cost allocation; see bundle COGS.
• Know your breakeven discount. Use a fee calculator to see the lowest price that still beats removal or disposal. Our FBA fee and profit calculator does this per ASIN.
• Remove or dispose deliberately. A removal order has fees and claim windows. Track the units from order to receipt so you can claim if some never arrive.
• Order smaller, more often. Overbuying to hit a supplier discount can cost more in surcharges than it saves. Include storage and aging risk in your purchase math.
• Set reorder points from real lead times. Too-low stock triggers stockouts, and too-high stock triggers aging. Inventory numbers that update from your books make this much easier.
• Consider the channel. Slow movers sometimes do better on another channel or via FBM. Our FBA vs FBM comparison covers the tradeoffs.

Our perspective: aging inventory is a data problem first

We see the same pattern with sellers who come to us. The surcharge itself is rarely the biggest loss. The bigger loss is not knowing, because settlements were posted as one net number, units were quietly lost in transit, and COGS sat in a spreadsheet nobody updated.

We built BeanHawk around the view that three records have to agree: what you bought (PO and landed cost), what Amazon says it holds (inbound shipments and ledger events), and what your accounting software shows (settlements, fees, COGS). When they disagree, one of two things is true. Either you made a bookkeeping error, or Amazon owes you money. You cannot tell which without the data side by side.

Our advice is to pick a monthly date, review age buckets and the surcharge line, and decide SKU by SKU: sell, discount, remove, or hold. Do not let a surcharge decide for you. And before you write off a single missing unit, check whether it is claimable.

, Tim

Where BeanHawk fits

BeanHawk monitors inbound shipments and FBA ledger events, claims lost and damaged inventory you are owed, and posts summarized settlements to QuickBooks and Xero for each sales channel. It also tracks POs and landed costs, manages COGS, and sends reorder alerts. Pricing is flat and we never take a commission on recovered funds. Plans run $0 (Free), $19 (Starter), $49 (Growth) and $99 (Scale) per month, based on order volume; see pricing. To see what Amazon may already owe you, start with the free FBA reimbursement audit.

FAQ

When does inventory become aged on Amazon?

The aged inventory surcharge applies to units stored for 181 days or more, with the rate rising in steps. The biggest jump comes after day 270. Check the FBA Inventory tool for the exact dates of your units.

Is the aged inventory surcharge part of COGS?

No. It is an operating expense, like storage fees. Putting it in COGS inflates the cost of goods sold and understates gross margin, which makes product-level profitability hard to read.

Can I write off aged inventory on my taxes?

Only if the loss is real and documented, such as disposal, destruction, or a valuation method that allows a lower value. Being old alone is not enough. Ask your CPA before taking a significant write-down, and check for an Amazon reimbursement first.

What is a healthy inventory turnover for FBA?

Many sellers aim for 6 to 12 turns a year, and under 4 is a warning sign. Durable goods can be healthy at 2 to 4 turns, so set the target by category, margin and lead time.

How do I keep aging inventory out of my books?

Reconcile Amazon’s inventory and settlement reports to your ledger monthly, record each fee in its own expense account, and review age buckets before units hit day 181. Our seller accounting library has step-by-step guides.

Sources

• Amazon seller forum: aging inventory action plan and 2026 fee tiers
• Amazon seller forum: FBA Inventory Age & Excess Analytics
• Sell on Amazon: A guide to Amazon FBA fees
• IRS Publication 538, Accounting Periods and Methods
• Ledger Labs: Accounting for Amazon Sellers
• Taxstra: Amazon Seller Tax Guide
• Monaco CPA: Amazon FBA CPA
• Register Company: Amazon FBA refund and reimbursement policy guide
• Threecolts: Inventory turnover ratio for Amazon FBA
• ProfitHawk: Amazon FBA inventory turnover
• Inventory Hero: Inventory turnover ratio

Recommended

• What is Aged Inventory Surcharge?
• Amazon Fees Accounting for Sellers: Five Step Tax
• Amazon Inventory Ledger for FBA Sellers
• Amazon Lost Inventory: What FBA Sellers Must Do