A physical inventory count is physically counting the units you hold and comparing that count to what your records say you should have. The difference reveals shrinkage, damage, miscounts, and unrecorded transactions. It is how you keep your inventory records honest, because records drift from reality over time, and a wrong on-hand number distorts every reorder, valuation, and profit figure that depends on it.
What is the difference between a full count and cycle counting?
Andrew Erickson is the founder of Inventory Hero. He has spent years working with Amazon FBA sellers on demand forecasting, restock planning, and the cash flow side of running a private-label brand. Inventory Hero exists because every spreadsheet-based inventory system he tried eventually broke — usually right before Q4.
A full physical count counts your entire inventory at one time, usually annually, often requiring a pause in operations. Cycle counting counts a portion of your inventory on a rolling schedule, so a slice is verified continuously without shutting down. Cycle counting catches errors sooner and is less disruptive, which is why most growing sellers prefer it, while a full count may still be needed for year-end accounting.
How do you count FBA inventory you cannot physically see?
You cannot physically count stock sitting in Amazon's fulfillment centers, so you reconcile against Amazon's reports instead. Pull the inventory reports (such as the Inventory Ledger and Manage FBA Inventory) and compare Amazon's counts to your records, and file reimbursement claims for units Amazon lost or damaged. Your own physical counts then cover any stock you hold outside FBA, at a prep center, a 3PL, or your own warehouse.
Read article
A physical count of inventory verifies what you actually have against what your records say, catching the shrinkage and errors that make records drift from reality. The short version: a full count counts everything at once while cycle counting counts a portion on a rolling schedule, cycle counting suits most sellers, and for FBA stock you reconcile against Amazon's reports rather than counting the warehouse yourself. Below are the methods, reconciliation, and the FBA wrinkle.
Every inventory record drifts from reality over time. Units get damaged, miscounted, stolen, or moved without a record, and each event opens a gap between your system's number and your real stock. A physical count closes that gap.
It matters because a wrong on-hand number quietly breaks everything downstream: your reorder point fires at the wrong time, your valuation and profit are off, and you either overbuy or stock out on bad data. Counting is the unglamorous discipline that keeps the numbers you manage on honest.
There are two ways to count, and the choice shapes how disruptive the discipline is:
Full physical count. You count your entire inventory at one time, usually annually, often pausing operations to do it. It gives a complete snapshot but is disruptive and infrequent, so errors can accumulate for a long time between counts.
Cycle counting. You count a portion of your inventory on a rolling schedule, a few SKUs or one location per day or week, so the whole catalog gets verified over a cycle without a shutdown.
Cycle counting wins for most growing sellers because it catches errors continuously and spreads the work out, though a full count may still be required for year-end accounting.
A count is only useful if you act on the difference it reveals:
Count the actual units for the SKUs or location in scope.
Compare to your records for the same items, and note every difference.
Investigate the gaps. A shortfall is shrinkage, damage, theft, or an unrecorded sale; an overage is a miscount or unrecorded receipt.
Adjust your books with an adjustment entry so your records match reality.
Fix the cause where you can, because a recurring gap points to a process problem, not just a one-off.
Worked through: your records say 100 units, you count 87, a 13-unit gap, or 13 percent shrinkage on that SKU. That is big enough to investigate in order: an unrecorded damage pull, a mis-pick on a recent order, or a data-entry error on the last receipt. You post the 13-unit adjustment so the books match the shelf, then fix whichever cause you find. The reconciliation, not the counting, is where the value is: an accurate count you never post changes nothing.
Here is the FBA-specific wrinkle: you cannot walk into Amazon's fulfillment centers and count your stock. So for FBA inventory you reconcile against Amazon's reports instead:
Claim lost and damaged units. Where Amazon's count is short because it lost or damaged stock, file a reimbursement rather than just writing it off. Amazon's "lost" and "damaged" buckets have different claim paths, and there is a filing window (on the order of a year and a half from the event), so reconcile and claim regularly rather than letting discrepancies age out.
Physically count what you hold elsewhere, at a prep center, a 3PL, or your own warehouse, since that stock you can actually see.
So an FBA seller runs a hybrid: real physical counts on stock they hold, and report reconciliation on stock at Amazon.
Frequency should follow value and risk, not a single calendar rule:
Count your A-items more often. Your highest-value, fastest-moving SKUs deserve a frequent cycle (say monthly), because an error there costs the most and they turn over fast enough to accumulate one.
Count the long tail rarely. Low-value C-items can go on a slow cycle (quarterly or at year-end), since an error there matters less.
Trigger a count on a signal. A stockout that should not have happened, or a reorder that felt wrong, is a reason to count that SKU now regardless of schedule.
Track your accuracy rate. Measure how often your count matches your record; a falling accuracy rate is the sign to count more often or fix a process leak.
The goal is not to count everything constantly; it is to verify the stock that matters often enough that errors are caught while they are small. Tie the cadence to your product segmentation, and let value decide.
Physical counts of inventory verify what you actually have against your records, catching the shrinkage and errors that make records drift. Cycle counting suits most sellers by catching errors continuously without a disruptive full shutdown, and the value is in reconciling and fixing the cause, not just counting. For FBA stock you reconcile against Amazon's reports and claim lost units, while counting what you hold outside FBA yourself. It is the foundation of inventory accuracy that every other decision depends on. Accurate counts keep your replenishment honest, so for the full FBA restock loop see FBA restock planning.