Net Margin Repricing: How to Stop Your Repricer from Selling Below Your Profit Floor
A repricer set to a typed floor sells below cost the moment any input changes. FBA fees increased in January 2026. COGS rises on the next supplier order. The typed floor does not update. The repricer keeps running at the number you entered six months ago, generating below-target margin on every competitive event where a competitor goes low.
Net Margin Repricing solves this. The floor is not a typed number. It is a formula: (landed cost + FBA fee) divided by (1 minus referral fee rate minus target margin rate). Every time an input changes, the floor recalculates. The repricer holds at this floor regardless of competitive pressure below it.
TL;DR
Net Margin Repricing sets your minimum price from live unit costs and a target margin percentage, so a competitor pricing below your floor cannot make your repricer follow them down. The floor recalculates when you update COGS or when Amazon's fees change. The mechanism is available in Repricer.com's Profit Protection feature. Configure it in three steps: enter landed cost per SKU, verify the calculated floor, and run Safe Mode for seven days before going live.
How Net Margin Repricing Pulls Live Unit Costs From Your ERP or Inventory System
Net Margin Repricing takes three categories of cost input: two come from Amazon, and one is supplied by you.
Amazon inputs:
FBA fulfilment fee: the current rate for each ASIN's size tier
Referral fee: the category commission percentage, which varies by category
Seller-supplied inputs:
Landed cost per SKU: COGS from the supplier plus inbound freight, duty, and prep costs. This is the total unit cost to get the product into an FBA fulfilment centre
Optional inputs:
Returns provision: the return rate you expect for the category
ERP integration: unit costs held in a supported inventory system, such as Linnworks or Extensiv, import into Repricer.com automatically via the integrations page
When Amazon publishes a fee change, the FBA fee input for the affected ASINs updates and the floor recalculates. When COGS changes on your next supplier order, you update the landed cost manually, through a CSV bulk upload, or automatically if an ERP integration is active. The floor recalculates as soon as the new cost is saved.
You set the target margin percentage once per SKU or once per category. It is the profit the floor enforces: the floor will not go below the price that produces this margin given the current cost inputs.
The Mechanism: Cost Data to Floor Calculation to Automatic Enforcement
The floor is a live calculation, not a stored number. Changing any input changes the floor, and the repricer enforces the new floor on the next pricing event.
The calculation for each ASIN runs like this:
Read the current FBA fee for the ASIN
Read landed cost from the cost input (ERP sync or manual entry)
Apply the referral fee rate for the category
Apply the target margin percentage from the repricing configuration
Calculate the floor: (landed cost + FBA fee) divided by (1 minus referral fee minus target margin)
Evaluate the competitive pricing event against this floor
If the competitive target price is above the floor, apply it. If below, hold at the floor
That is the complete mechanism. The floor is always the price that achieves the target margin given current inputs, so the repricer never holds at a price built on outdated cost data. For the feature itself, see Profit Protection.
Four Habits That Protect Margin
Margin protection comes down to four habits: set a floor from your costs, refresh it when fees move, read what competitors are doing below it, and compete on more than price. Net Margin Repricing automates the first two. The last two are yours.
1. Set a minimum price from your costs, and stick to it
A floor typed in on the day you set up is accurate for exactly that day. A floor calculated from landed cost, fees and a target margin stays accurate because it moves with the inputs. Build the floor per ASIN with the formula above, then leave it alone. The point of a floor is that it is not a negotiating position. If you lower it every time a competitor drops, it stops protecting anything.
For a step-by-step guide to the cost stack, see how to calculate your minimum price.
2. Refresh your floors whenever Amazon's fees change
Amazon typically announces fee changes in the fourth quarter, with new rates taking effect in January. Every increase raises the price you need to hit your target margin, which is why our guide to Amazon seller fees suggests a calendar reminder each October.
The January 2026 changes show how uneven the effect is. Amazon raised FBA fulfilment fees by an average of $0.08 per unit from 15 January 2026, according to Supply Chain Dive, but a small item priced above $50 rose by $0.51 while a large item below $10 did not change. As an illustration, a $0.51 increase left uncorrected at 200 units a month costs $102 per ASIN every month in margin you did not plan to give away.
3. Watch what competitors do below your floor
You cannot control a competitor's price, but you can read it. Repricer.com shows competitor prices in real time and lets you filter by fulfilment type, seller rating and location, so you can tell a seller who genuinely competes with you from one who does not. Then watch what the below-floor competitor does next. Do they sell out, raise their price, or stay low for weeks? The section on what happens when a competitor undercuts your floor, later in this guide, covers each case.
4. Compete on more than price
When the floor holds and a competitor stays below it, price is not your only way to win. Amazon weighs fulfilment method, seller performance metrics, shipping time, feedback and inventory depth alongside price, and our Buy Box guide shows how each factor works. Strengthening those factors lets you win the Buy Box at a price that still meets your margin target. If your floor sits above the whole competitive range, the product has a sourcing margin problem that repricing alone cannot solve.
Want help setting floors on your own catalogue? Book a Demo.
A Worked Example: Product Cost, FBA Fees, and the Floor That Protects Both
A standard-sized product with a $12.80 landed cost and a $4.50 FBA fee needs a $23.07 floor to deliver a 10% margin. The inputs for this US marketplace example are:
Landed cost: $12.80
FBA fee: $4.50
Referral fee rate: 15%
Target margin: 10%
Floor calculation:
Total variable costs: $12.80 + $4.50 = $17.30
Floor = $17.30 divided by (1 - 0.15 - 0.10) = $17.30 divided by 0.75 = $23.07
A competitor prices at $19.99. The repricer holds at $23.07. The sale at $19.99 would generate:
Revenue: $19.99
Referral fee (15%): $3.00
FBA fee: $4.50
Landed cost: $12.80
Net profit: -$0.31 (margin negative)
At $23.07, the sale generates:
Revenue: $23.07
Referral fee (15%): $3.46
FBA fee: $4.50
Landed cost: $12.80
Net profit: $2.31 (10.0%, target margin achieved)
Now suppose the FBA fee rises from $4.50 to 5.00forthissizetier.Thenewflooris(12.80 + $5.00) divided by 0.75 = $23.73. Without Net Margin Repricing, the typed floor of $23.07 would still enforce, and every sale at $23.07 would generate $1.81, a 7.8% margin instead of the 10% target. With Net Margin Repricing, the floor updates to $23.73 when the new fee is applied.
How to Configure Net Margin Repricing in Repricer.com
Setup takes three steps and applies to any catalogue size. Net Margin Repricing is available in Repricer.com's Profit Protection feature.
Step 1: Enter landed cost. In the Repricer.com dashboard, open Profit Protection and enter landed cost per SKU: COGS from the most recent supplier invoice plus inbound freight, duty, and prep. For catalogues above 50 ASINs, use the CSV bulk import template. For live COGS updates without manual entry, connect your inventory management system via the integrations page.
Step 2: Set target margin and verify the floor. Enter the target margin percentage per SKU or per category. The dashboard calculates and displays the resulting floor for each ASIN. Cross-check the displayed floor against the current Buy Box price range on five representative ASINs. The floor should sit below the competitive market range. A floor above that range points to a sourcing margin problem that repricing cannot fix.
Step 3: Run in Safe Mode first. Enable Safe Mode before switching to live repricing. In Safe Mode, the repricing engine runs the full floor calculation and competitive response against real Amazon pricing data without making any changes to live listings. After seven days, compare the simulated average selling price to the actual average selling price from the same period. When the simulation confirms the margin outcomes you expect, enable live repricing.
Book a Demo to see Net Margin Repricing configured on your own catalogue in Safe Mode. The demo shows the floor calculation on real ASINs with your cost inputs before any live prices change.
What Happens When a Competitor Undercuts Your Floor
When a competitor's price drops below your floor, the repricer holds at the floor. This is the correct outcome, because a sale below the floor does not meet the margin target. Three scenarios follow from a below-floor competitive event:
The competitor holds below your floor. They may win the Buy Box at a price that would be margin negative for you. Your listing stays above that price and no sale occurs at the below-floor price. The alternative, following them down, would generate a sale that erodes margin or delivers a loss.
The competitor returns above your floor. They sell out, raise their price, or lose Buy Box eligibility. The market returns above your floor, and the repricer wins the Buy Box at a price that meets the margin target.
Several competitors hold below your floor for an extended period. This signals either a temporary event, such as a competitor liquidating stock, or a structural sourcing margin problem: the market price has fallen below the level where the product delivers your target margin at current costs. If it keeps happening on an ASIN, review sourcing rather than lowering the floor. Lowering the floor to match the market generates sales at below-target margin, which defeats the purpose of floor enforcement.
Repricer.com's analytics let you filter your catalogue by profit margin, ROI, stock level and cost, and track Buy Box ownership over time, which helps you spot the ASINs where this is happening.
Key Takeaways
A typed floor becomes wrong every time a cost changes. A floor left unchanged since December 2025 protects less margin than intended on every ASIN whose fee increased.
The correct floor formula is (landed cost + FBA fee) divided by (1 minus referral fee rate minus target margin rate). It is the price at which a sale achieves the target margin after all variable costs.
Net Margin Repricing calculates the floor live. When a fee or your COGS changes, the floor recalculates.
A competitor pricing below your floor cannot make your repricer follow them down. The below-floor sale does not happen, which is the correct behaviour.
Safe Mode is the correct starting point. Run it for seven days, compare simulated and actual average selling price, then enable live repricing.
Action Plan
Calculate the correct floor for your top 10 ASINs using (landed cost + FBA fee) divided by (1 minus referral fee minus target margin). Compare the result to your current typed floor. The gap is the per-unit margin you are giving up on every sale at the typed floor.
Check whether the January 2026 fee increase affected your floors. The increase ranged from no change to $0.51 per unit depending on size and price band. If a typed floor has not been updated since December 2025, it is wrong on every affected ASIN.
Enter landed cost for your top 10 ASINs in Profit Protection. Landed cost is COGS plus inbound freight, duty and prep.
Set a target margin per ASIN or category and verify the calculated floor against the current Buy Box price range.
Enable Safe Mode for these 10 ASINs and run it for seven days. Compare simulated average selling price to the actual figure.
Enable live Net Margin Repricing when the simulation confirms acceptable outcomes, then extend to the full catalogue through CSV bulk import.
Connect your ERP through the integrations page to automate COGS updates. Without it, update landed costs manually after every supplier order that changes your unit cost.
Frequently Asked Questions
How do I stop my repricer from selling below cost? Configure Net Margin Repricing in Repricer.com's Profit Protection feature. Enter your landed cost per SKU, set a target margin percentage, and the floor calculates as (landed cost + FBA fee) divided by (1 minus referral fee minus target margin). The repricer holds at this floor on every competitive event, so a competitor pricing below it does not trigger a price response below the floor.
What is Net Margin Repricing? Net Margin Repricing is a method of setting repricing floors from live cost inputs and a target margin percentage, rather than from a typed minimum price. When any input changes, the floor recalculates, so an FBA fee increase raises the floor on affected ASINs and a COGS change feeds through as soon as the new cost is saved. The floor is always the price at which a sale achieves the target margin given current costs.
How does a profit floor work in automated repricing? A profit floor is the minimum price the repricer enforces. With a typed floor, it is a static number entered once and updated by hand when costs change. With Net Margin Repricing, it is a calculation that runs on every pricing event from current cost data. The repricer refuses to price below it regardless of competitive pressure.
What should a good profit floor include? A good floor covers the full Amazon cost stack: landed cost, the FBA fee, the referral fee, and a returns provision where relevant. A floor built from COGS alone misses the fees Amazon takes from every FBA sale, so it sits below true break-even. Ask any repricer two questions: does the floor recalculate when Amazon changes fees, and does it use per-SKU cost inputs?
What happens if every competitor undercuts my Net Margin floor? The repricer holds at the floor and does not generate a sale at the below-floor price. If it persists, the market price has probably fallen below the level where the product delivers your target margin at current cost, and the right response is a sourcing review, not a lower floor. Repricer.com's analytics can show you which ASINs sit at low margin.
Book a Demo to see Net Margin Repricing on your own catalogue in Safe Mode, with the floor calculation running on real Amazon pricing data. No prices change during the Safe Mode session.
