Questions to Ask a 3PL Before You Sign: The Complete Vetting Checklist

Before you sign with a 3PL, you need clear written answers in five areas: pricing and fees, performance SLAs, technology and integrations, scalability, and support. Providers all sound similar on a sales call; the differences show up in how specifically they answer the questions below. Use this checklist in your evaluation calls and ask for the answers in writing — anything a 3PL won't put in writing, assume you won't get.

What pricing questions should you ask a 3PL?

1. Can you model my total monthly invoice from my last 90 days of orders — not just quote unit rates?
2. What accessorial fees exist beyond receiving, storage, and pick/pack? (Ask for the complete fee schedule.)
3. What are your monthly minimums, and what happens in months I don't hit them?
4. How do storage rates change during peak season (Sept–Jan)?
5. What carrier discounts do you pass through, and at what markup?
6. How and when can rates change after I sign?

Benchmark their answers against current market rates in How Much Does a 3PL Cost in 2026?

What performance and SLA questions matter most?

7. What is your order accuracy rate, and how is it measured?
8. What's your cutoff time for same-day processing?
9. What's your dock-to-stock time for inbound inventory?
10. What happens when you miss an SLA — credits, escalation, or apologies?
11. Can I see your actual performance reports from the last peak season?

A provider that hits 99%+ accuracy and same-day processing will show you the data without flinching. If you're switching because your current 3PL misses these, read How to Switch 3PL Providers Without Disrupting Fulfillment.

What technology and integration questions should you cover?

12. Do you have native integrations with my platforms (Shopify, Amazon, TikTok Shop, WooCommerce, retail EDI)?
13. How fast does inventory sync back to my store — real time, hourly, nightly?
14. Can I see live inventory, orders, and exceptions in your dashboard?
15. How do you handle address validation and order edits after checkout?
16. What happens to orders when an integration goes down?

How do you test whether a 3PL can scale with you?

17. What was your peak daily order volume last Q4, and at what accuracy?
18. How much notice do you need for a 3–5x volume spike?
19. Can you support new channels later — wholesale/B2B, subscriptions, marketplaces?
20. Do you require long-term contracts, or can I stay month-to-month? (Why this matters: 3PL Companies With No Long-Term Contracts.)
21. What's your labor plan for peak — temp-heavy or trained core staff?

What support questions reveal the real relationship?

22. Who is my point of contact — a named account manager or a ticket queue?
23. What's your average response time on order-level issues?
24. How do you communicate problems proactively (shorts, damages, delays)?
25. Can I talk to two current clients my size, and one that left?

That last one is the single highest-signal question on this list. Any confident 3PL can produce happy references; how they handle the churn question tells you how they'll handle bad news when you're the client.

FAQ

How many 3PLs should I evaluate?

Shortlist 3–5, get modeled invoices from all of them, and do deep-dive calls with your top two. More than that and the comparison gets noisy.

Should I visit the warehouse before signing?

If the volume justifies it, yes — or ask for a live video walkthrough. You're looking for organized bins, clean receiving docks, and staff who aren't surprised to see a tour.

What's the biggest red flag in a 3PL sales process?

Refusing to model your total invoice or share the complete fee schedule. Hidden pricing before you sign becomes hidden fees after — see Why Cheap Fulfillment Becomes Expensive Over Time.

How long should onboarding take?

2–4 weeks is standard for a straightforward DTC catalog. Get the onboarding plan — with owners and dates — in writing before you sign.

Want to see how Atomix answers all 25? Book a call — we'll bring the fee schedule.