Should You Switch FBA Prep Partners for 2027? Here's How to Decide

We are well into planning season, and wouldn’t be surprised if you had a few renewal quotes in your inbox. You’re building your Q1 budget and somebody on your team is inevitably going to propose moving prep partners.

A lot of those proposals are coming from a bad month in Q4 and an over-simplified rate card. But, be wary of a transition that’ll get you a whole new set of problems.

If you’re trying to decide whether to stay or switch your FBA prep partner in 2027, here’s how we would run a review. Use this guide to evaluate whoever you’re considering, as well as your current provider.

Find the issues before you evaluate

Before anything else, you should have a crystal clear picture of your current state. That includes what is going well (that you don’t want to give up) and what is going wrong.

Pull at least 90 days of your own operating data. Separate ordinary weeks from launches and peaks, and you may want to analyze Q4 as a unit. If your provider handles low volume well and a high-volume week poorly then it’s likely a capacity problem rather than a process problem, which would be fixed differently.

Measure:

• receiving time, from dock to Amazon check-in
• prep cycle time, from inventory receipt to ship to Amazon
• receiving time, from provider ship to Amazon check-in
• defect rate: labels, carton content, prep
• chargebacks by root cause and by dollars
• invoice variance against the signed rate card
• response and resolution time on exceptions

Think about each of these issues with your current data and ideal state. For example, instead of saying “FBA prep is taking too long,” say “our median dock-to-receipt is 15 days and we need that to be less than 10.”

Once you know where you stand and where you want to be, start running through these checks.

Check one: Amazon check-in times

“Fast check-in” means at least four different things, and providers are rarely asked which.

ZonPrep’s internal data shows average check-in times without ZonPrep ranging from 7 to 43 days. It takes such a large range because your inventory needs to go through this process:

1. Your provider receives your inventory
2. Your provider preps the inventory for FBA
3. Your provider sends the inventory into Amazon
4. Amazon checks-in your inventory and makes it available for purchase

Some providers might say they’re fast but only be talking about step 2. Others could say they’re fast but they just mean from their receipt to Amazon check-in. Get those details and timelines clarified in writing.

Then ask for median and 90th-percentile performance. Averages usually hide the best and worst, and the worst is what you want to plan for. They may give you this in peak vs non-peak windows for more clarity.

For reference, ZonPrep has a 5-day guarantee for when products get to us to when they’ll get to Amazon. That means once we’ve gotten your inventory at a ZonPrep facility it won’t take more than 5 days for that inventory to arrive at Amazon.

Note that providers cannot guarantee time to Prime, as that is an internal Amazon metric. This refers to the time products are checked-in and available for sale on Amazon to when they become Prime eligible.

Check two: Fully functional facilities

A sales deck could list facilities that are planned, at half capacity, partner sites that aren’t ready yet, and much more that won’t yet be available to you. Instead of relying on the hopes and dreams of a provider, ask for:

• the full operating address, and whether the site is owned, leased, subcontracted or planned
• which specific site would receive each of your SKUs
• what that site handles today: programs, shipment modes, prep types, category restrictions
• current receiving and outbound capacity, not designed capacity, plus cutoffs and holiday calendar
• proof of insurance, category certifications, and a live tour or a recent timestamped walkthrough
• where your volume routes if that building stops operating

Be cautious if a site is subcontracted, since that means a second set of SOPs, staff, and some loss of visibility and ownership in your supply chain.

Check three: Fair commercial terms

Logistics are some of the stickiest providers, because they have all of your inventory, are trained to your SLAs, and since you’re already working with them it makes them the safe choice when there’s a toss up.

Be on the lookout for consistent billing and any future increases. For example, a rate match is an acquisition play. Many companies make a conscious decision to match a rate they can’t sustain and then bump prices up after that.

Tip: Take a real invoice from last quarter and ask the provider what it would have cost and how quickly it would have been done with their team.

Include transition fees in your overall budget

Don’t focus too much on what your speed and costs would be once you’re fully up and running with your new provider. You can’t just snap your fingers and be fully operational. Price out how much the transition itself will cost, and what you’re willing to budget for it.

Plan for the physical count and discrepancy resolution, transfer freight and repalletizing, aged or damaged stock, systems and Vendor Central setup, SKU master and packaging-rule migration, new labels and materials, a period of dual-running two partners, staff time, and buffer inventory to cover the gap.

If you want to go a step further, divide your annual run-rate benefit by total transition cost. Include the expected reduction in chargebacks and rework with conservative assumptions. If it’ll take a whole year to earn back the transition cost then consider renegotiating with that information in hand.

When to stay with your current FBA prep partner

Your current partner already carries your SKU list, packaging rules and every exception your catalog has taught them. That institutional knowledge is worth real money, it took time to build, and none of it transfers cleanly. A challenger starts at zero on all three, and the first ninety days of any new relationship are the worst ninety days of it.

If the root cause of your main issue is understood and it is not structural, it could be worth staying. A failed integration, a staffing gap, or a site that was wrong for your mix are fixable. If they just lack capability, then you’ll need to switch sooner rather than later.

The other thing worth checking before you move is your own operations. If you have switched prep partners twice in three years, take a look at what you can be doing better. Do you have irregular replenishment? Do you schedule arrival days on a Friday that pushes freight into the next week?

We wrote up some of the factors you can control to optimize your inbound speeds at How to Reduce FBA Inbound Times for Amazon Sellers.

When to switch to a new FBA prep partner

If the issue that triggered the switch is structural, then don’t fall for the sunk-cost fallacy. These are issues like the capability you need does not exist and is not being built, facilities cannot be verified, SLA misses repeat against a definition both sides agreed to, evidence does not appear when a chargeback lands, invoice variance is chronic, renewal economics no longer work and will not move, or the contract behavior makes next year riskier than the transition itself.

These are all especially bad when your partner isn’t willing to take accountability and figure out how to prevent future mistakes of the same nature. Those are pretty clear signs it’s time to make a switch.

What next?

If you’d like to see what your numbers could look like, ZonPrep provides an FBA opportunity analysis that will look at your placement fees, receiving time, and more compared to what we would have been able to deliver. You can check it out with an easy Chrome extension here.