Amazon FBA Q4 Prep Checklist for Online Arbitrage Sellers

1. Why 90 Days Is the Right Window for Q4 Prep

Q4 starts October 1. If you're reading this in late July, you have exactly the right amount of runway. Not so early you're speculating on products that don't exist yet, and not so late you're buying in a panic.

Most sellers wait until September to think about Q4. By then, prep centers are booked solid, inventory limits are already getting tight, and every good ASIN has three more sellers piling on. You're playing catch-up before the season even starts.

I did $140K in revenue last Q4. The prep work started in July. This checklist is what I actually ran through, in order. Use it the same way.

2. Step 1: Audit Your Cash Position Right Now

Before you source a single unit for Q4, you need to know exactly what you're working with. Pull your bank balance, your available credit, and your open Amazon reimbursement claims. Write down three numbers: liquid cash today, cash accessible in 30 days, and expected Amazon payouts over the next 60 days.

Q4 is a cash-flow game. You can have $50K tied up in inventory and still run out of buying power if your payout cycle doesn't line up with your buying schedule. Sellers who hit this wall in October don't recover in time for the Black Friday window.

If you're under $5K liquid right now, your Q4 goal is to keep flipping inventory fast enough to fund larger buys in October. Set a weekly reinvestment target - not monthly. Monthly is too slow. You need to see the number move every seven days.

For a deeper look at managing cash across your selling cycle, the FBA cash flow post breaks down exactly how I time payouts to buying cycles.

3. Step 2: Build a 50-ASIN Sourcing Backlog Before August

Q4 inventory needs to be inside Amazon's warehouse by mid-October to catch the full holiday sales window. That means you're sourcing now and shipping in August and September. You do not have time to research products in October.

Build a list of at least 50 ASINs you've verified as profitable in the last 90 days. Focus on products with a 90-day sales rank under 100,000 in their category and a minimum $8 net profit per unit. Q4 velocity is high, but margins compress fast as more sellers pile in. You want products with enough margin cushion to absorb that compression and still clear $5 net.

The point of the backlog is speed. When a deal drops, you should be able to make a buying decision in under 60 seconds because you've already done the research. Pre-vet first, buy when the price is right.

The sourcing tools breakdown covers the exact software stack I use to build and maintain this list every week.

4. Step 3: Lock In Your Prep Center Before August Ends

If you're prepping yourself right now, Q4 is when that decision becomes a real problem. You physically cannot prep 300-plus units a week by yourself and also spend 6 hours a day sourcing. The math doesn't work.

"I'm going to teach you how to find a reliable prep center for your Amazon FBA business, because it's not an easy task but it's something that you will have to do eventually if you want to scale your business." Chris Mangunza, How to Find a Prep Center for Amazon FBA Online Arbitrage (July 2023)

Good prep centers fill up in Q4. I've talked to sellers who called in September and couldn't get onboarded until after Thanksgiving. That kills your entire November. Do not let that be you.

Contact at least three prep centers before August is over. Ask specifically: what is your Q4 capacity limit, what is your per-unit price for standard and oversize, and what is your average turnaround from receiving to shipping? You want 48 to 72 hours max. Anything slower than that is a problem in a high-velocity season.

The full vetting process for finding a prep center that won't slow you down is in the prep center guide here.

5. Step 4: Know When to Stop Prepping Yourself

There's a real debate in the FBA community about when to make the move to a prep center. Some people want to outsource on day one. Others insist you should be doing it yourself indefinitely. Both extremes are wrong.

"If you have the choice when you start, you should start by prepping yourself if you are in the US... but on the other end you have the hardcore guys on Twitter saying that hey, you should really be in the trenches for super long." Chris Mangunza, When Should You Get a Prep Center? (June 2023)

The rule I use: prep yourself until you're consistently moving 100 units a week. At that point, the time cost of prepping starts eating directly into sourcing hours, and the ROI flips hard in favor of outsourcing.

By Q4, if you're over 100 units per week, a prep center isn't optional. It's required. If you're still early and under that number, use Q4 to push volume through yourself and track every hour you spend on prep. That data tells you exactly when to make the switch.

6. Step 5: Fix Your Inventory Performance Index Before October

Amazon's restock limits will shut you down in Q4 if your Inventory Performance Index score is in bad shape. Log into Seller Central right now and check your IPI score and your storage-type restock limits. You have 90 days to fix problems before they matter most.

If your IPI is under 400, the fix is the same every time: clear slow-moving inventory. Run a price drop, create a removal order, or pull units back to FBA from your home. Whatever it takes to move stale stock and get that score up. A healthy IPI going into October means more room to send inventory during the season's peak weeks.

Also check your standard-size and oversize limits separately. A lot of sellers don't realize the limits are by storage type. You might have room for 2,000 standard units but be capped at 300 oversize. That matters if any of your Q4 products are in large categories like toys or home goods.

7. Step 6: Order Supplies Before the September Rush

Poly bags, bubble wrap, packing tape, thermal label rolls - prices spike and availability drops every September when every FBA seller on the planet orders at once. Buy in bulk now and skip that headache.

My standard pre-Q4 supply order: 1,000 poly bags in assorted sizes, 2 cases of 2-inch clear packing tape, 4 rolls of bubble wrap, and a 6-month label roll for my Rollo thermal printer. Total cost runs me about $175 to $190 on Amazon Business. I place this order every year in late July without thinking about it.

If you're moving to a prep center this year, you still need supplies for receiving and quick-checking product at your home location before you ship out. Don't skip this step just because you're outsourcing the main prep work.

8. Step 7: Set Your Repricing Rules Before Q4 Volatility Hits

Q4 price swings are real. An ASIN you're used to netting $9 on can jump to a $22 net in 48 hours when supply gets tight, then crash back down a week later. If you're manually repricing through all of that, you're going to miss moves or panic-sell at the wrong moment.

Before Q4, set floor and ceiling rules in your repricer. My Q4 floor is never below $7 net profit per unit, regardless of what the Buy Box competition is doing. My ceiling allows up to 2x my normal price if the Buy Box supports it. You do not want your repricer racing to the bottom against other sellers while demand is spiking.

Flag your top 20 ASINs for a manual price check every morning during November. Automation is good, but Q4 has demand spikes that algorithms catch slowly. A manual check takes 10 minutes and can save you from underselling on your best movers for days at a time.

9. Step 8: Know Amazon's Q4 Shipping Cutoffs Cold

Amazon publishes holiday shipping cutoff dates each year, but most sellers don't look at them until it's too late to act. The dates that matter most for 2026:

• Black Friday: November 27, 2026
• Cyber Monday: November 30, 2026
• Last FBA inbound for guaranteed Prime Christmas delivery: typically December 1-5 depending on the fulfillment center
• Standard shipping cutoff for Christmas delivery: typically December 18-19

Work backward from those dates on your own prep timeline. If your prep center needs 5 days to process a shipment, you cannot send inventory after late November and expect it to be in stock for Cyber Monday. That window closes faster than most sellers realize.

The last week of November is the highest-velocity selling window of the year. You want your inventory already live in the warehouse, not sitting in an inbound shipment with a status of "receiving."

10. Step 9: Build a Cash Reserve for the Thanksgiving Week Window

Black Friday and Cyber Monday are when you want maximum buying power, not when you're waiting on a payout. Time your October inventory buys so you clear a payout in the first two weeks of November. Then hold part of that cash back.

"Scaling this business is easy - you just need to spend more money in inventory. That's it. You just need to spend more money in inventory to be able to scale your Amazon FBA business." Chris Mangunza, You Will Never Scale Your Amazon FBA Business (April 2024)

I keep $10K to $15K in liquid reserve specifically for November 27 through December 2. That week, retail clearance prices crater because stores are running their own sales, but Amazon sell-through is at peak demand. It's the best 5-day sourcing window of the entire year, and most sellers miss it because they're tapped out from October buying.

If you're not at $10K liquid yet, that's fine. Set a target and work toward it. Even $2K to $3K reserved for that window will put you ahead of the sellers who spent everything in October and can't buy a single unit when the best deals appear.

11. Step 10: Switch to Weekly P&L Reviews Starting Now

Monthly P&Ls are too slow for Q4. You need to see your numbers every 7 days during October and November. An ASIN that hasn't moved in 3 weeks during Q4 is already costing you money in storage fees and tying up capital you could be flipping into faster-moving products.

Every Monday morning, pull three numbers: your sell-through rate by ASIN, your inbound versus available unit counts, and your average net per unit for the prior week. That review takes 20 minutes with a basic spreadsheet. The inventory management guide has a template you can copy if you don't have one set up yet.

Set a hard rule for yourself: if any ASIN sits at zero units sold for 14 consecutive days during Q4, you drop the price immediately. No debating, no waiting for one more week. Q4 velocity is high enough that a profitable product should be moving. If it isn't, something is wrong with the price.

12. Next Steps

Q4 is 90 days out and the sellers who start prep now are the ones who have inventory in stock and cash on hand when November hits. The sellers who wait until September are always playing catch-up.

If you want to watch me work through a real Q4 sourcing session and buying plan live, grab a free seat at the Thursday training at ngunza.com/register. I run the whole session in real time, including which products I'm stacking for Q4 and why.

Five posts to read next:

• How to Find a Prep Center for Amazon FBA Online Arbitrage
• Amazon FBA Cash Flow: How to Never Run Out of Buying Power
• The Sourcing Tools I Use Every Day for Online Arbitrage
• Amazon FBA Inventory Management: How to Track What's Working
• Amazon FBA Online Arbitrage: The Complete Beginner's Guide