FIFO Costing

The true cost of every unit you sell

Your supplier prices change. SellerGuards tracks every purchase as a dated lot and consumes them oldest-first — so each Amazon sale is costed with the exact lot it came from. Real cost of goods, honest margins, tax-ready profit.

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FIFO lotsWE-220COST OF GOODS TODAY$19.50● Active lotDec 5, 2025● ACTIVE · NEXT OUT$19.50Amazon Wholesale Co · Dec 5, 202520 / 50 leftQUEUED · POS #2$20.50BulkBuy Distributors · Feb 20, 2026Qty 60 · waitingCOMPLETED$18.00Wholesale Direct · Nov 10, 202540 / 40 sold
Why it matters

You bought the same SKU at three different prices

So when a unit sells, what did it actually cost you? Guess wrong and every margin, P&L and pricing decision is off.

Average cost smears the truth

Blending every purchase into one number hides that your costs are climbing. Margins look stable while your real profit quietly erodes — and your COGS won't hold up at tax time.

FIFO uses the real cost

SellerGuards assigns the cost of the actual lot being sold, oldest-first — the way your stock physically moves. Every order shows what that unit truly cost, and your COGS is accounting-correct.

How it works

Sales drain the oldest lot first

Three lots of the same SKU, sorted by purchase date. Watch where today's cost of goods comes from.

Units soldStill in stockTODAY'S COST OF GOODS$19.50 — from Lot 2 (active)COMPLETED$18.00Nov 10, 202540 / 40 sold● ACTIVE$19.50Dec 5, 202530 / 50 soldQUEUED$20.50Feb 20, 20260 / 60 soldFirst in (oldest)Last in (newest)Sold units always drain the oldest lot first — its unit cost becomes your cost of goods (First In, First Out).
The Lots panel

Every lot, grouped by where it is in the queue

Open any SKU and the Lots panel lays out its cost history in FIFO order — what's selling now, what's next, and what's done. Search by supplier or unit cost, and edit, transfer or remove a lot anytime.

Active

Active lot. Marked Next out — units are deducted from this lot first. The bar shows how much is sold and how many pieces remain.

Queued

Next lots. Waiting in FIFO order. The moment the active lot empties, the next-oldest lot becomes active automatically.

Done

Completed lots. Fully consumed and kept for history, so past orders always trace back to the exact cost they were sold at.

SellerGuards Lots panel showing an active lot, queued next lots in FIFO order, and completed lots
Worked example

Follow 70 units as they sell

Here's exactly how FIFO assigned cost to the units sold so far in the example above.

1

Units 1–40 → Lot 1 @ $18.00

The oldest lot (Nov 10) is drained first. After 40 sales it's fully consumed and moves to Completed.

2

Units 41–70 → Lot 2 @ $19.50

Costing rolls onto the Dec 5 lot. 30 units sold so far, 20 still remaining — this is the Active lot.

3

Next sale → still $19.50, then $20.50

The next 20 units keep the $19.50 cost. Once Lot 2 empties, the Feb 20 lot becomes active at $20.50.

Units soldFrom lotUnit costCOGS
40Lot 1 · Nov 10$18.00$720.00
30Lot 2 · Dec 5$19.50$585.00
70 totalavg $18.64$1,305.00
A blended-average tool would put the same cost on every unit and miss that your price moved from $18.00 to $20.50.
What each lot stores

A few fields, total cost accuracy

Record a purchase once and SellerGuards handles the costing from there.

Supplier

Who you bought from, so you can compare costs across vendors over time.

Unit cost

The exact per-unit price for that purchase — the cost FIFO assigns while the lot is active.

Quantity & remaining

How many units the lot held and how many are left, with a live sold-through bar.

Purchase date

Drives FIFO order — lots are consumed oldest-first by the date they came in.

Expiration date

Optional, for perishable or dated stock — so you can act before inventory expires.

Status & position

Active, queued or completed, plus its place in line so you always know what sells next.

The payoff

Why FIFO costing changes the numbers you trust

True per-order profit

Every order's net profit uses the real cost of the lot it sold from — not an estimate.

Honest margins as prices rise

When supplier costs climb, your margins reflect it immediately instead of lagging behind.

Tax-ready COGS

FIFO is a recognized accounting method, so your cost of goods sold is ready for the books.

Smarter pricing

Know your real floor before a price drop or promo turns a winner into a loser.

Supplier comparison

See how each supplier's unit cost flows through to actual profit, lot by lot.

Capital & expiry clarity

Know how much cash each lot ties up and which dated stock needs to move first.

Connected

FIFO cost flows everywhere it's needed

Record a lot once and the right cost shows up across the whole platform.

Orders →

Per-order net profit and margin use the exact FIFO cost of the units sold.

Inventory →

Average cost, stock value and capital locked are all driven by your real lots.

Profit & Loss

True COGS rolls up into an accurate P&L you can actually file from.

Cost every sale at what it really cost you

Add your purchase lots and SellerGuards does the FIFO math on every order, automatically.

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