kitting & fulfillment
Top 5 Mistakes to Avoid When Planning Your Subscription Box Fulfillment
Launching or scaling a subscription box brand is exciting. But if you don’t nail the subscription box fulfillment side of things early on, you risk frustrated customers, shipping delays, and costly mistakes.
At Sidekick Kitting, we’ve worked with subscription box companies of all sizes—from new startups to national brands like Science Friday and Barnes & Noble.
And after fulfilling millions of boxes, we know exactly where things can go wrong—and how to keep you far, far away from those pitfalls.
Here are the top 5 mistakes brands make with subscription box kitting and fulfillment, and how to avoid them like a pro.
1. Underestimating Assembly Time

“It’s just putting stuff in a box, right?”
Wrong. So wrong.
Subscription box kitting is way more complex than it looks—especially if your box includes:
- Products from multiple vendors
- Custom inserts
- Specially layered packaging
- Branded touches like belly bands or stickers
Every extra SKU adds complexity. And every added detail (even crinkle fill!) adds time.
Real Talk from Sidekick:
When we worked with Science Friday on their STEM-themed subscription kits, we weren’t just packing items—we were carefully arranging delicate science gadgets, test tubes, and info cards.
Luis and Alejandro on our warehouse floor made sure every assembly line was dialed in so that 5,000+ kits shipped out perfectly and on time.
Pro Tip:
Build realistic timelines that account for kitting complexity, not just shipping deadlines. Or better yet—let Sidekick Kitting handle it. We love the complex stuff.
2. Not Planning for Inventory Delays
You can have the best subscription box idea in the world—but if your inventory shows up late (or wrong), your whole fulfillment timeline crashes.
We’ve seen it all:
- Mugs stuck at customs
- Notebooks printed with the wrong logo
- Inserts that arrived with typos
- Vendors sending half the quantity you ordered
Real Talk from Sidekick:
That’s why Bruno, our inventory expert, is a hawk when it comes to intake. He triple-checks incoming shipments so that if anything’s off, we catch it early—before it impacts your ship date.
Pro Tip:
Always build a 1–2 week inventory buffer. Work with a 3PL (like Sidekick Kitting!) that inspects every shipment immediately.

3. Ignoring Packaging Details

The unboxing experience is everything for subscription brands.
If your boxes look cheap, disorganized, or arrive damaged, you lose trust instantly—even if the products inside are amazing.
At Sidekick Kitting, we obsess over:
- Crinkle fill placement
- Tissue folds
- Sticker alignment
- Product layering (so the prettiest thing pops first!)
Real Talk from Sidekick:
When Minny & Paul launched one of their big seasonal gift campaigns with us, we spent extra time prototyping box layouts to get the presentation just right—because first impressions matter.
Pro Tip:
Always plan (and budget for) beautiful, on-brand packaging. Sidekick can help you design it, source it, and assemble it perfectly.
4. Choosing the Wrong Fulfillment Partner
Most 3PLs are built for basic e-commerce—not subscription boxes.
You don’t want to be one of 500 clients fighting for attention at a giant fulfillment center that’s optimized for “grab and ship” orders.
You want a team that specializes in subscription box kitting, like Sidekick Kitting:
- We thrive on projects with multiple SKUs.
- We love custom packaging challenges.
- We assign real people—like Annie and Jen—to manage your project (not a random ticketing system).
Real Talk from Sidekick:
We’ve helped brands recover from fulfillment disasters caused by “big box” 3PLs that didn’t get the complexity needed. We love coming in, fixing the process, and making your next launch your best one yet.
Pro Tip:
Interview your 3PL carefully. Ask about their kitting experience. Ask how many SKUs per order they can handle confidently.

5. Skipping Quality Control

You can have the perfect products, perfect packaging, and perfect inventory—but if nobody double-checks the final box, you still risk big problems.
Missing items. Damaged goods. Incorrect versions. All of these are fixable before a box ships—if someone’s paying attention.
Real Talk from Sidekick:
We have built-in multi-step quality control on every project:
- Bruno oversees pre-kitting inventory checks.
- Luis and Alejandro audit assembly lines during production.
- Our team spot-checks finished boxes before they leave the warehouse.
We treat your subscription box like it’s our own—and we won’t ship anything that doesn’t meet our (very high) standards.
Pro Tip:
Ask your 3PL what their quality control steps are. At Sidekick, we’ll walk you through every checkpoint we hit to protect your brand.
Planning Subscription Box Fulfillment the Sidekick Kitting Way
Subscription box fulfillment is high-stakes.
Your customers expect magic every month.
We make sure you deliver it—beautifully, reliably, and at scale.
- Detailed inventory intake
- High-energy, fast-moving warehouse floor (thank you Luis and Alejandro!)
- Meticulous project management (shoutout to Annie and Jen!)
- Multi-layered quality control (Bruno's superpower)
- Scalable capacity (up to 10,000 boxes/day)
- Women-owned and proud
When you work with Sidekick Kitting, you’re not just outsourcing fulfillment—you’re gaining a true partner who loves your brand as much as you do.
Let's Build Your Best Subscription Box Yet
Avoid the common mistakes.
Partner with a team who’s been there, done that, and still gets excited about every box.
👉 Contact Sidekick Kitting today to talk about your next subscription box project.
We can’t wait to kit for you!