Solo and operator-led sellers
Replace the spreadsheet that follows every inbound shipment with a workflow that protects packing time and contribution margin.
MarginLock for FBA
Lock your margin. Ship your shipments.
MarginLock is the fulfillment + margin protection platform for Amazon FBA sellers — settlement reconciliation, fee detection, reimbursement automation, and a packing UI built for warehouses.
Built for serious FBA sellers
One operating loop for packing, shipping, and margin review.
Catalogs with repeat inbound volume
Keep carton selection, prep gates, placement choices, and settlement review from drifting into separate tools.
Small warehouse teams
Give packers a clear shipment flow while owners can still see the financial outcome after Amazon receives stock.
Three pillars
Everything an FBA team actually needs
Inbound workbench
Plan, prep, and pack shipments without spreadsheets. Bin packing, label generation, and box-compliance gates in one pass.
Bin-packing engine
Automatic carton selection that respects Amazon's box weight and dim limits — fewer rejected shipments, fewer reboxing rounds.
Settlement reconciliation
Match every payout line back to the order, return, or fee that produced it. Discrepancies surface automatically.
Fee detection
Continuous audit against the Amazon fee schedule. Catch overcharges the moment a settlement lands.
Reimbursement automation
Detect lost, damaged, and overcharged inventory. Generate cases, file them, and track recovery without manual logs.
Compliance gates
Box weight, hazmat prep, and dim-tier rules enforced before a label prints. No more punitive penalty fees.
FBA operating loop
The same shipment record follows the work from shelf to settlement.
MarginLock is designed around the way FBA teams actually work: choose stock, pack cartons, keep Amazon compliance gates active, and review the money trail after the shipment leaves.
- 01
Choose the SKUs that are ready to move
Inventory, reserved units, prep requirements, and inbound-plan status stay in one workspace before a carton is opened.
- 02
Pack cartons with compliance gates active
Weight, size tier, prep category, hazmat, and mixed-box rules are checked before labels print.
- 03
Create and ship the FBA plan
Amazon inbound milestones, placement decisions, labels, and shipment status are tracked as one operating loop.
- 04
Reconcile the money trail afterward
Settlements, fee drift, reimbursement candidates, and per-SKU contribution margin are reviewed from the same source of truth.
Margin watchdog
Get paid for what you sold — and what Amazon owes you.
Most FBA tooling stops at order ingestion. MarginLock keeps going: every fee, every reimbursement, every settlement line tied back to its source. When margins move, you see it the same day — not at month-end.
- Tracks every fee dimension Amazon charges (storage, fulfillment, returns, removals, IPI).
- Reimbursement detection across lost, damaged, and overcharged scenarios.
- Per-SKU margin cards with cost-of-goods, fees, returns, and net contribution.
MarginLock
Margin watchdog
Live demo data
Settlement reviewed
$8,420
Fee drift: +3.1%
FBA fee variancereview
Lost inbound unitsok
Return processing feeok
Attention
2 reimbursement candidates
The exception is attached to the shipment record so the operator can resolve it before the workflow moves forward.
52.5 lb
overweight warning threshold
Cartons approaching Amazon penalty territory are flagged before a label is generated.
1 screen
for packing and margin review
Warehouse actions and post-shipment reconciliation share the same shipment record.
48 hr
sandbox demo window
Evaluate the operating flow with seeded FBA data before connecting Amazon.
Learn before you connect Amazon
Evergreen FBA operations guides support the self-serve funnel.
The website should earn trust before signup. These resources connect seller search intent directly to the product workflows that solve the problem.
Bin-packing fundamentals
How FBA cartons should be grouped, weighed, and validated before labels print.
Settlement reconciliation
A practical guide to matching Amazon settlement lines back to orders, returns, and fees.
Reimbursement workflow
What to check when inventory is lost, damaged, overcharged, or not reimbursed cleanly.
Stop leaking margin.
Run MarginLock against your live Amazon account in minutes. Sandbox demo available — no credit card.