Negative inventory is one of the most common (and frustrating) issues teams run into—especially when you’re exporting settlements to QuickBooks or reviewing an inventory report and see a negative quantity on an item. The good news: in ConnectBooks’ inventory system (ConnectStock), every transaction is traceable from purchase to sale. Use the steps below to find the cause and fix it quickly.
Quick checklist (start here)
Identify where it’s negative
Go to your Inventory report and note which warehouse (Local, In Transit, FBA) is negative for the item.
Verify listing ↔ item mapping
In ConnectStock: Navigate to Items → search the item → Click on View listings. Confirm:Multi-pack/group items are set correctly (no double-multiplying).
Units of measure is set up correctly
The listing’s pack quantity matches how the item is purchased.
All linked listings actually belong to this SKU.
Example of Mistakes: If you buy the item as a 10-pack and also set the listing to quantity 10. One sale can remove 10 × 10 = 100 units by mistake.
Confirm FBA setups (if FBA is involved)
FBA Shipments: Make sure all shipments are transferred, none ignored from the inventory file start date, and they’re posted to the correct warehouse.
Beginning balances: Make sure your file has beginning inventory adjustments for all warehouses as of the file start date:
a Local beginning adjustment,
an FBA beginning adjustment, and
a second FBA adjustment 40 days in to account for all items that were in transit as of the start date
If the above looks good, go deeper with the steps below.
Step-by-step: Trace the problem
1) Filter the Inventory Detail Report
Open Inventory Detail.
Enter the item and filter to the warehouse that's negative.
You’ll now see every transaction affecting that item in that warehouse (from the beginning of time to now).
What to look for:
Beginning balance present? (e.g., “Beginning Adjustment: 1,000 units”)
Ins/Outs that don’t make sense? Missing bills, unexpected adjustments, incorrect FBA shipments, etc.
Warehouse mistakes on bills: A very common cause.
Never post a vendor bill directly to FBA.
Receive into your Default (source) warehouse first; FBA shipments then move inventory to In Transit → FBA.
Tip: It can be easier sometimes to export the report to Excel and sort by date or transaction type.
2) Fix the root cause
Depending on what you find:
Wrong listing mapping/pack size: Correct the listing. ConnectBooks will recalculate all transactions on this listing, you will just have to update the existing FBA adjustments to fix current counts.
Bill in the wrong warehouse: Edit/move the receipt to Local and let the FBA shipment handle the transfer. you might need to redo the adjustments if this item inventory was miscounted.
Missing bills or over-stated adjustments: Enter the missing receipt(s) or correct the sales/adjustments.
Ignored FBA shipments: Click Transfer on the shipments. you might need to redo the adjustments if this item inventory was miscounted.
If you still can’t find it
Option A: Roll forward from your last reconcile date
Pick the last date your ConnectStock inventory matched reality (e.g., July 1).
Run Inventory Detail from July 1 forward on the item/warehouse.
Review each transaction after that date to see if anything looks off or if a transaction is missing.
Option B: No reconcile date? Create a new one.
If you don’t have a verified baseline, you’ll chase ghosts. So do this:
Physical count in Local → post a new Inventory Adjustment to your local warehouse to match actual inventory.
FBA Adjustment → Create a new FBA adjustment to be in line with Amazon as of the same date.
Use Clear Negative Inventory if any items are still negative.
From today forward, watch Inventory Detail to catch any new negatives quickly.
Special cases to check
FBA quirks
Amazon can over- or under-receive FBA Shipments, and reports don’t always add up perfectly. If In Transit or FBA stays negative (or oddly positive):
Open Shipment Discrepancy page, and reconcile all FBA shipments discrepancies.
Example: You sent 100 units, Amazon received 20—reconcile the 80-unit difference according to Amazon’s final disposition.
Multiple warehouses
Always isolate the issue by warehouse first. A healthy Local balance can hide a negative in FBA or In Transit.
Prevention tips (so it doesn’t happen again)
One source of truth for packs: Define pack size once and make listings match. Avoid double-multiplying quantities.
Receive to Local first: Post all vendor bills to Local, never to FBA.
Use transfers, not shortcuts: Let the FBA shipment move stock from Local → In Transit → FBA.
Close and reconcile FBA shipments regularly: Clear discrepancies promptly.
Keep a standing reconcile cadence: Monthly (or more often) verify Local, In Transit, and FBA; post adjustments as your baseline.
Audit mappings after catalog changes: Any time you add group items, bundles, or new listings.
Bottom line
Negative inventory always traces back to a specific transaction or setup: mapping/pack mistakes, bills in the wrong warehouse, unposted FBA movements, or missing beginning balances. Follow the flow above—identify the warehouse → validate mapping → trace transactions—and you’ll pinpoint and fix the issue quickly.