Quick Answer:
If your package weighs more than the amount covered by your original shipping label, Mercari lets you cancel the label and purchase a new one with the correct weight and postage. To do this, update the shipping weight in the app, generate a new label, and reprint it. Mercari uses flat shipping rates through USPS, UPS, and FedEx, so it’s important to select the correct weight when listing or shipping to avoid delays and extra fees.
Introduction: Why Shipping Label Issues Happen on Mercari
If you’ve sold on Mercari before, you know that shipping labels are usually simple: Mercari provides prepaid labelsbased on the weight you entered when listing the item.
But what happens when:
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📦 The package is heavier than expected?
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✍️ You selected the wrong weight at listing?
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📤 USPS or UPS says “insufficient postage”?
In these cases, you’ll need to request a new shipping label with more postage to ensure your package gets delivered — and your buyer gets their item on time.
This guide explains how to fix Mercari shipping label issues, generate a new label, avoid extra costs, and keep your seller rating intact.
Why You Might Need a New Mercari Shipping Label
Mercari shipping labels are automatically generated based on weight and shipping method you chose when listing. You may need a new label if:
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You underestimated the weight of the package.
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You added extra packing materials that increased the shipping weight.
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The carrier refused the package due to insufficient postage.
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You selected the wrong shipping method (e.g., USPS instead of UPS).
📝 Example:
You listed a sweater as 1 lb. But after packing it with a box and tissue, it weighs 2 lb. The original label is insufficient, and Mercari requires you to update the weight to generate a new label.
Automate this with Closo → Closo can help you keep track of weights, shipping costs, and margin calculations across platforms automatically.
How Mercari Shipping Labels Work
Mercari offers three primary shipping options:
| Carrier | Weight Range | Label Provided By | Notes |
|---|---|---|---|
| USPS | 0–150 lbs (Flat tiers) | Mercari | Most common for lightweight packages |
| UPS | 0–150 lbs | Mercari | Good for heavier items |
| FedEx | 0–150 lbs | Mercari | Typically cheaper for larger boxes |
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Buyers can pay for shipping or sellers can offer free shipping.
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Labels are auto-generated based on selected weight.
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If the actual package is heavier than the selected weight, you’ll need a new label.
What Happens If Postage Is Insufficient
If your package doesn’t have enough postage, one of three things can happen:
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Carrier Returns the Package: USPS or UPS rejects the package, marking it “postage due.”
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Postage Due Notification: You may receive a notification that the buyer has to pay additional postage — which is bad for seller ratings.
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Delivery Delays: Packages may be held at the carrier facility until corrected.
❌ Underpaid postage can:
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Delay delivery,
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Lower your seller rating,
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Lead to refunds or cancellations.
✅ Always weigh your package after packing, not before.
How to Request a New Label on Mercari
Follow these steps if your package exceeds the original weight limit.
🧭 Step-by-Step:
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Open the Mercari App or Desktop
Go to “Selling” → select the relevant order. -
Tap “Need a New Label”
This option appears if the order hasn’t shipped yet. -
Update the Weight and Dimensions
Adjust the package weight to reflect the actual packed weight. -
Select a Carrier (if needed)
Switch from USPS to UPS or FedEx if that’s cheaper or required for the new weight. -
Generate a New Label
Mercari will cancel the previous label and create a new one with the correct postage. -
Reprint & Ship
Print the new label and drop off the package.
🚨 Important:
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You can’t downgrade postage — only upgrade.
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The difference in postage cost will be deducted from your earnings.
Mercari Shipping Rates by Weight
Mercari’s prepaid labels are based on flat-rate tiers.
| Weight Range | USPS | UPS Ground | FedEx Home | Notes |
|---|---|---|---|---|
| 0–0.5 lb | $4.87 | $7.99 | $8.25 | Apparel, accessories, light items |
| 0.5–3 lb | $7.49 | $9.95 | $10.65 | Most common shipping weight |
| 3–10 lb | $10.95 | $13.50 | $13.90 | Larger items, bundles |
| 10–20 lb | $17.95 | $21.95 | $22.35 | Heavy boxes |
| 20–50 lb | $35.00+ | $40.00+ | $42.00+ | Oversized |
(Prices may vary slightly over time due to carrier updates.)
Automate this with Closo → Closo helps sellers auto-calculate weight tiers and postage to avoid unnecessary relabeling.
Can You Change a Mercari Shipping Label After Purchase?
Yes, but with limits.
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You can generate a new label with more postage before shipping.
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You cannot modify an already shipped package.
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You can switch carriers if it’s cheaper for the new weight.
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If the buyer has already received a tracking number, the old one is voided after label replacement.
⚡ Pro tip: If the weight is only slightly off (e.g., 1.1 lb on a 1 lb label), Mercari often still recommends updating the label to avoid carrier fees.
How to Avoid Label & Weight Issues
🏋️ 1. Weigh Everything After Packing
Always weigh your item in the box with all packing materials included.
📦 2. Round Up
If the weight is close to the next tier (e.g., 0.98 lb), round up to avoid issues.
🚚 3. Use UPS or FedEx for Heavy Packages
They can be cheaper for heavier items compared to USPS.
🧾 4. Track Shipping Costs in Real Time
Knowing your shipping cost before listing can help set the right price.
🧠 5. Use Tools Like Closo
Closo’s shipping calculator and listing optimizer can help reduce relabeling errors and protect your profit margins.
FAQ
❓ Why does Mercari say I need a new label for more postage?
It means your package weighs more than the weight selected at listing. You’ll need to generate a new shipping label with higher postage.
❓ Can I change my shipping label on Mercari?
Yes, you can cancel the old label and generate a new one before shipping.
❓ Who pays for the extra postage?
If the seller underestimates the weight, the seller pays the difference, deducted from earnings.
❓ Will the buyer be notified?
Yes, the tracking number will update automatically once a new label is generated.
❓ How can I avoid this in the future?
Weigh your item after packing and round up to the next tier. Use accurate scales to avoid mistakes.
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🏁 Final Thoughts
Needing a new Mercari shipping label for more postage is a common and fixable issue.
The key is accuracy at listing time and flexibility before shipping:
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🧾 Always weigh after packing.
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✍️ Update the label before the package hits the carrier.
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📈 Use the right carrier to keep costs low.
For resellers, shipping mistakes can cut into profit margins quickly. By using tools like Closo, you can automate shipping calculations, track weight tiers, and make smarter listing decisions that minimize relabeling and maximize profit.
