How to organize eBay inventory: SKUs, bins, and locations.

A SKU is a code you choose for an item or product. eBay's Trading API guide describes SKUs as values defined by sellers to help track products and inventory, and it lists the field as Item.SKU with a maximum length of 50 characters.¹ In the seller screens the same idea appears as the Custom label (SKU), which is visible in Seller Hub under Listings, Active.²

The same guide says it is logical to use a unique SKU value for each item or product, but that eBay does not enforce this, except for multiple-variation listings, where each variation should have its own SKU.¹ In other words, eBay will not stop you from reusing a code, so any scheme that keeps codes distinct is up to you.

When a sale comes in, you need to find a single item among everything you own. If the SKU starts with a code for a bin or shelf, the listing itself tells you where to look. You do not need to search by title, remember where a thing went, or open a separate spreadsheet. This is our suggestion, not an eBay requirement: eBay leaves the contents of the field to you.

The idea works the same for a garage, a closet, a rented shelf, or a storage unit. Pick a short code for each place, write it on the bin or shelf, and start the SKU of every item in that place with the same code.

Here is a scheme we suggest. Build each SKU from two parts, a location prefix and a tail that is never repeated:

• Prefix: a short code for where the item is stored, such as A12 for bin A, shelf 12. Keep it the same for every item in that spot.
• Tail: something that differs for each item, such as the date you listed it plus a counter.

As a sample, A12-15OCT26-03 reads as bin A12, listed on October 15, 2026, third item that day. Because the tail is unique, two items in the same bin still get different SKUs, and the prefix lets you gather everything in one bin.

Keep the whole code short enough to read at a glance and to stay under eBay's 50 character limit for the field.¹ Short codes are also easier to write on a bin label and to read aloud.

These are practical suggestions from us, not eBay rules:

• Do not reuse a SKU for a different item. eBay does not enforce uniqueness for single listings,¹ so two different items can end up with one code and you will not be warned. Searching that code later then returns both.
• Do not put a price or your cost in the SKU. A price baked into a code goes out of date as soon as you change the listing, and a cost figure is something you may not want printed anywhere.
• Do not rename bins without updating listings. If a shelf is renumbered, the codes on existing listings still point to the old name. Pick stable names first.
• Avoid look-alike characters. The letter O and the number 0, or I and 1, are easy to misread on a handwritten label.

In a US eBay seller account checked on October 15, 2026, the Custom label (SKU) was visible in Seller Hub under Listings, Active, and searching for part of a SKU there found the matching listings.² That means a prefix such as A12 can pull up the listings you stored in that bin. Screens change, so check your own account.

For the packing step, the packing slip options in the same account included Custom label, and the option was off by default.³ If you turn it on, the code can print on the slip, so whoever packs the order sees the bin code and can walk straight to the shelf.

Packing is also where supplies run out. See the shipping supplies guide for boxes, mailers, and labels, and use the eBay fee calculator to test a price before you list.

On each draft, Strooply has an optional SKU prefix field. You type a prefix of up to 30 characters. When the listing is created, the app adds the date (in your account's time zone) as DDMMMYY and a number that counts up through the day. As a sample, the prefix A12 gives A12-15OCT26-03. Leave the prefix empty and the SKU is just the date and number. The date and number tail keeps each SKU unique in your account, so two items with the same prefix never share a SKU. A 30 character prefix plus the tail stays under the 50 character limit in eBay's guide.¹

A draft also has a separate Storage location text field, for a note such as Bin A1. It is its own field and is not added to the SKU, so if you want the bin to show in Seller Hub, put the same code in the SKU prefix. See how Strooply works for the rest of the listing flow.