Prepare RFID tags for your products

Each product variant needs an RFID tag whose EPC encodes the product's EAN or UPC. Existing tags work fine; they just need to be re-encoded with the right EPC. There is no need to source new blank tags. Any UHF RFID tag you already have that allows EPC writes will do.

The process has two steps:

Convert the product's EAN or UPC into an EPC string
Write that EPC to the tag

How to convert EAN or UPC to EPC

Use the genepc CLI.

Install the CLI tool once: npm i -g @dim2k/genepc-cli
Run genepc <ean-or-upc> to convert a value
The generated EPC is automatically copied to your clipboard

For example, running genepc 52578029 returns the EPC 3000000140E9280000000000 and copies it to your clipboard.

If the product has only a UPC and no EAN, pass the UPC directly. genepc pads any input to the 14-digit GTIN length, so you do not need to manually prepend a zero.

How to write the EPC to a tag

Use JADAK Universal Reader Assistant (URA). URA works with a wide range of UHF RFID readers and writers, so any compatible reader or writer you have on hand should work.

Connect the reader or writer to the computer using USB or network
Open URA and let it detect available devices
Select your reader or writer from the connection list and connect to it
Go to the Write EPC tab
Bring the tag close to the reader's antenna; close enough to be in the read field, but ideally with no other tags nearby
Click Read first to verify the tag is detected. The current EPC value should appear. If nothing appears, reposition the tag and try again
Paste the EPC generated with genepc into the new-EPC field
Click Write
Click Read again to verify; the EPC should now match what you wrote

The tag is now ready to be attached to the product.

Notes

Any UHF RFID tag whose EPC bank is not locked can be re-encoded; you do not need new tags
Keep one tag in the read field at a time during a write. Multiple tags can be written to simultaneously, which is usually undesirable
If URA does not see your reader, your hardware vendor may ship a proprietary writing tool. Use that vendor tool with the same EPC string from genepc