SKU guide
Reseller SKU system for eBay, Poshmark, and Mercari
Use one clean SKU system before listings spread across marketplaces. The code should help you find the item, not become another place for records to drift.
Quick take
- Create the SKU before crosslisting so every marketplace copy points back to the same item.
- Use eBay Custom Label and Poshmark private SKU fields where they fit, but keep one source item record outside the marketplaces.
- Use Resylr when you want SKUs, bins, labels, Order Picking, profit, finance, and tax-ready records kept together.
Steps
- 1
Create one source item record
Add photos, title, condition, cost, SKU, bin, and notes before publishing the item anywhere.
- 2
Assign a short SKU
Use a unique code that is easy to read while picking orders. Keep bin location as a separate field so items can move without changing the SKU.
- 3
Map the SKU to each marketplace
Use eBay Custom Label where available, Poshmark private SKU fields where available, and your source item record for marketplaces that do not expose the same SKU workflow.
- 4
Label before storage
Tag or label the item before it goes into a bin, shelf, or rack so the sold-item workflow stays reliable.
- 5
Test the sale workflow
Confirm you can see what sold, find the item, pack it, review profit, and keep the record trail clean.
Use one SKU before the item spreads
The mistake is waiting until the item is already live on eBay, Poshmark, Mercari, and a spreadsheet. Give the item one internal SKU first, then let each listing copy point back to that same record.
What the marketplaces give you
eBay Seller Hub reports include a Custom Label field, and eBay bulk listing templates use Custom label (SKU). Poshmark has private listing fields for SKU, cost price, and notes, plus inventory reports that include SKU. Mercari gives sellers listing and sales-report data such as item ID, title, order status, price, shipping, and fees, so the safest workflow is to keep your SKU in the source item record and use marketplace fields only where they clearly support it.
- eBay: use Custom Label or SKU when it fits the listing workflow.
- Poshmark: use the private SKU field so buyers do not see internal codes.
- Mercari: keep the SKU in your source record and tie it to the Mercari item ID after listing.
- All marketplaces: avoid relying on the public description as your only inventory system.
Do not make the code too clever
A SKU should be easy to read and unique. It does not need to hold every detail about brand, size, source, cost, category, and bin. Put those details in the item record where they can change without breaking the code.
- Use short IDs such as A0042, J-128, or R2026-091.
- Keep bin, shelf, or rack as a separate location field.
- Keep cost, fees, shipping, and profit in the item record.
- Print or write the SKU on the item label before storage.
Where Resylr helps
Resylr keeps the SKU, bin, listing copies, sold status, labels, Order Picking, profit, finance, receipts, mileage, and tax-ready records closer together. That matters when the same physical item is live in more than one marketplace.
When a spreadsheet can still work
A spreadsheet is fine when inventory is small and updates are easy. Move to a connected system when sold items, bin moves, marketplace IDs, profit, labels, and records are taking more time than the listing work itself.
FAQ
Can I use the same SKU on eBay, Poshmark, and Mercari?
Yes. Use one internal SKU for the physical item, then map it to each marketplace copy. eBay supports Custom Label or SKU workflows, Poshmark has private SKU fields, and Mercari can be tied back through your source item record and item ID.
Should my reseller SKU include the bin number?
Usually no. Keep the SKU unique to the item and keep bin, shelf, or rack as a separate location field. That way you can move inventory without renumbering the item.
How do I find sold items faster when crosslisting?
Create the SKU before listing, label the item before storage, keep the bin in the item record, and use one sold-item queue. Resylr helps when SKUs, labels, Order Picking, profit, finance, and records should stay together after the sale.