SKU generator
Build a batch of clean, consistent codes for your inventory — pick a format, set your prefix, then copy them or download a CSV that imports straight into a spreadsheet.
PF-0001
Runs PF-0001 through PF-0025
Every code in this batch
Click one to copy itThe CSV carries a sku column plus blank name and cost columns, so it opens straight in a spreadsheet — or imports into PalmFlow in one click.
How to create SKUs for reselling
Four steps, and you only have to decide once. Nothing to install and no account.
- Choose a prefix. Your initials or your store name — two or three characters is plenty. It leads every code, so an item stays recognizably yours on a shelf full of other people’s tags.
- Pick a format. Sequential is the default for a reason. Switch to dated, category, or short codes if the table below describes your operation better.
- Set how many you need. Up to 500 at a time. Most sellers generate a run after a sourcing trip rather than one code per item.
- Copy the batch or download the CSV. The file carries a sku column plus blank name and cost columns, so it opens straight in a spreadsheet with room to fill in the rest.
SKU formats compared
Four shapes cover almost every reseller. Each example is exactly what the generator builds from a PF prefix.
Sequential and short codes answer the same question in opposite ways. A sequential run is easier for a person: you can read PF-0413 down a phone line, and you always know what comes next. A random short code is easier for a system: two people can tag boxes at the same time without colliding, and the code doesn’t publish how many items you’ve listed. Neither is wrong. What is wrong is switching between them halfway through a catalog.
What makes a good SKU
The best SKU format is boring. Short enough to read at a glance, long enough to stay unique, and identical in shape across every item you own. Cleverness is what kills SKU systems — a code that encodes six facts is a code nobody can read out loud, and a code nobody can read out loud is a code that gets mis-typed.
The rule that saves the most trouble later: never encode anything that can change. Price changes. Condition gets revised. Storage location changes the first time you reorganize the garage. A SKU carrying any of them stops being true the moment it does, and you’re left choosing between a wrong code and reprinting every label you own.
Rules that hold up as your catalog grows
- Keep it short.Six to twelve characters reads fast and prints small enough to fit on a tag alongside a size and a price.
- Skip look-alike characters.0 and O, 1 and I and L get mis-keyed and mis-scanned. Short codes from this generator leave all five out on purpose.
- Pad your numbers.0001 sorts correctly next to 0042. Unpadded, a spreadsheet puts 10 before 2 and the order you sourced in disappears.
- Pick one separator and keep it.A hyphen is the safe default. Mixing hyphens and underscores across a catalog breaks every lookup you will ever do on it.
- Don’t encode what moves.Price, condition, and location all change. The code that identifies the item shouldn’t.
- Be consistent.One boring format across the whole catalog beats a clever one you abandon in March.
SKU, UPC, or barcode?
A UPC — and its relatives EAN and GTIN — is a global product number issued through GS1 and printed on the packaging by whoever made the item. Every seller of that exact product shares it. A SKU is the opposite: it is yours, it is private, and it identifies one unit in your inventory, including the one-of-a-kind thrift find that has no UPC anywhere on it.
A barcode is neither. It is simply a way of printing a code so a scanner can read it, and it will happily encode either number. Most resellers end up using all three — the UPC to look a product up, the SKU to tie a unit to what they paid for it, and a printed barcode so the SKU gets scanned instead of typed.
Using SKUs on eBay, Poshmark, and Mercari
A SKU is internal, so nothing about it is marketplace-specific. What changes is whether the site gives you a field to keep it in.
- eBayThe field is called custom label. It sits on the listing form and in Seller Hub, buyers never see it, and it comes back on your Seller Hub reports and order downloads — which is what lets a sale be matched to the item’s cost without hunting for it.
- Poshmark and MercariWhere a SKU field is offered, use it. Otherwise the code lives on the item’s own tag and in your records, which is the part that matters anyway: it’s how a sold item gets found in a bin.
- Shopify, Etsy, and AmazonAll three have a field for your own code — SKU on a Shopify product and an Etsy listing, seller SKU on an Amazon offer — so a code generated here drops straight in.
Because the code is yours, the same one can sit on every channel at once. That is the whole point of having it: one item, one code, and a sale on any platform still leads back to what the item cost you.
Frequently asked questions
What is a SKU?
A SKU (stock keeping unit) is a short code you assign to an item so you can track it across your inventory, listings, and sales. Unlike a UPC or barcode set by the manufacturer, a SKU is yours — you choose the format. Resellers use SKUs to find an item on a shelf, match a sale back to its cost, and print scannable labels.
How do I create SKUs for reselling?
Pick a consistent format and stick to it. Most resellers use a short prefix (their initials or store name), then either a running number, the intake date, or a category code. This free generator builds that batch for you — set a prefix, choose a style, and copy or download as many as you need.
What makes a good SKU format?
Keep it short, consistent, and human-readable. Avoid characters that are easy to confuse on a printed label (0 vs O, 1 vs I vs L). Don't encode information that changes, like price or condition. A good SKU is unique, sortable, and quick to read out loud.
Should SKUs be sequential or random?
Sequential SKUs (PF-0001, PF-0002) are simple and sort in intake order, which is great for solo resellers. Random short codes (PF-4X7Q2) avoid collisions if multiple people add items at once and don't reveal how many items you've listed. Both work — pick one and be consistent.
How many digits should a SKU have?
Pad your number to as many digits as the largest inventory you expect. Four digits (0001–9999) covers most reseller catalogs and keeps codes sorting correctly. If you flip tens of thousands of items a year, use five or six.
Can I use these SKUs on eBay, Poshmark, or Mercari?
Yes. A SKU is your internal code, so it works on any marketplace. On eBay you can add it as the custom label; on other platforms you keep it in your own records and on the item's label. It's the thread that ties a listing back to your cost and profit.
Is this SKU generator really free?
Yes — no signup, nothing to install, and no card. Generate up to 500 codes at a time and as many batches as you like, then copy them or download the CSV. PalmFlow makes the free tools resellers actually use; the paid product assigns SKUs automatically and prints the barcode labels.
What is the difference between a SKU and a UPC?
A UPC — and its relatives EAN and GTIN — is a global product number issued through GS1 and printed on the packaging by whoever made the item, so every seller of that exact product shares it. A SKU is the opposite: it is yours, it is private, and it identifies one unit in your inventory, including the one-of-a-kind thrift find that has no UPC anywhere on it. Most resellers use both.
Where does the SKU go on an eBay listing?
eBay calls it the custom label. It sits on the listing form and in Seller Hub, buyers never see it, and it comes back on your Seller Hub reports and order downloads — which is what lets a sale be matched to the item's cost without hunting for it.
Can I generate SKUs in bulk?
Yes. Set how many you need and the whole batch is built at once, up to 500 codes at a time. Copy them all as a plain list, or download the CSV and paste the column straight into your spreadsheet. Most resellers generate a run after each sourcing trip rather than one code per item.
What is a good SKU numbering system?
The one you'll still be using in a year. A short prefix, a fixed-width number, and one separator covers almost every reseller: PF-0001 through PF-9999. Add structure only when it earns its keep — a category code if you store by department, an intake date if you want to see how long stock has been sitting.
Should a SKU use letters, numbers, or both?
Both is normal. Letters carry the meaning — a prefix or a category — and numbers carry the sequence. What matters more is skipping the characters that look alike on a printed label: 0 and O, 1 and I and L. Short codes from this generator leave all five out on purpose.
Can two items share the same SKU?
Only if they are genuinely interchangeable — same product, same condition, same cost. Most resale inventory is one-of-a-kind, so each unit gets its own code. Reusing a SKU across different units is the thing that makes cost basis and profit reporting go wrong months later, and it is very hard to unpick after the fact.
What separator should I use in a SKU?
A hyphen is the safest default: it reads clearly, survives spreadsheets, and is fine in an eBay custom label. Underscores and periods work too, and no separator at all is fine if your codes are short. Avoid spaces and slashes — those are the ones that cause trouble in file names, exports, and URLs.
Does this work for Shopify, Etsy, or Amazon?
Yes. All three have a field for your own code — SKU on a Shopify product and an Etsy listing, seller SKU on an Amazon offer — so a code generated here drops straight in. Because a SKU is internal, the same code can be used on every channel at once, which is the whole point of having one.
More free tools for resellers
Codes are the easy part.
PalmFlow assigns the SKU when you add an item, prints the label that carries it, and tells you what that item actually made when it sells.