Before you can file a warranty claim on a Poly or Plantronics headset, you need two things off the hardware itself: the serial number and the date code. Neither is where you'd expect, and the location changes by model — here's everywhere to look.
Quick answer
Last updated July 2026
What the two codes are
Date code: designates the date your headset was manufactured, and it's what HP uses to establish the warranty period. It's short — one letter and one number, like J7 — and usually printed alongside the model and part number, though not always.
Serial number: prefixed with S/N, in a format like S/N: AB0-000. This is the unique identifier for your specific unit.
Where to find them
There's no single location. It varies by model and by how old the headset is, so work through these until you find it:
- Inside the ear cup — remove the ear cushion first and check the inner part of the speaker housing.
- Inside the headband — on the inner surface.
- On the microphone boom arm — the inner side.
- On the in-line control unit — for USB headsets.
- On the back of the USB dongle — for wireless adapters.
- On the bottom of the base — for wireless headset systems.
- On the back or bottom of an amplifier base.
- On a tag along the cable — not all cables carry one.
Removing the ear cushion is the step most people skip, and it's where the label sits on a lot of corded models. The cushions pull off without tools and push back on the same way.
Myth
The date code is all I need — it proves when my warranty started.Reality
The date code proves when the headset was manufactured, not when you bought it. If a unit sat in a distributor's warehouse for several months, a warranty calculated from the date code is shorter than one calculated from your invoice. HP can run the serial number if you have no receipt, but it will use the manufacture date — so keep the invoice from your authorised reseller. It may also be requested as proof of origin.Decoding the date code
The letter-and-number combination maps to a specific manufacture date, but Plantronics has used different coding schemes across product generations, and we don't publish a conversion table here rather than risk giving you the wrong year on a warranty claim.
If you need the manufacture date decoded, HP support can do it from the serial number directly during a claim. If you bought from us, call with the code and we'll help identify it.
Where to look on older Plantronics models
On legacy headsets, the code location follows the product family:
- Supra — H51, H61, H51N, H61N
- Polaris — P51, P61, P51N, P61N, and the P31 and P31N
- Mirage — H41 and H41N
- TriStar — H81 and H81N, on the headset itself or on the Quick Disconnect
All of these are long discontinued, but the codes remain readable if you're identifying an old unit — worth doing before ordering replacement parts, since ear cushions and voice tubes differ between families. Our Polaris compatibility guide covers the P-series specifically.
What to do once you've found it
With the serial number and date code in hand, you can register the unit and file a claim through HP's support portal. Our Poly warranty claim guide walks through the full process, what's covered, and the exclusions worth knowing before you start.
Where is the serial number on a Plantronics headset?
It varies by model. Check inside the ear cup after removing the cushion, inside the headband, on the inner side of the boom arm, on the in-line control unit for USB headsets, on the back of a USB dongle, or on the bottom of a wireless base. You may need to check several locations.
What does a Plantronics date code look like?
One letter followed by one number, such as J7. It's usually printed alongside the model and part number, though not always. The serial number is separate and prefixed with S/N, in a format like S/N: AB0-000.
Does the date code determine my warranty period?
It determines the manufacture date, which HP uses to calculate warranty if you can't produce an invoice. That's usually shorter than a warranty calculated from your purchase date, so keeping the receipt from your authorised reseller protects your coverage.
I can't find the serial number anywhere on my headset. What now?
Check under the ear cushions first — it's the most commonly missed location on corded models. If it's a wireless system, check the bottom of the base rather than the headset. On very old units the label may have worn away, in which case call us with the model and we'll advise on options.
Where's the serial number on a wireless headset base or USB dongle?
On the bottom of the base for wireless headset systems, and on the back of the adapter for USB dongles. Amplifier bases carry it on the back or bottom.
Find the code, note it alongside your invoice, and the warranty claim itself is straightforward. If the label has worn off or you can't locate it, call our team at 877-999-3838 with the model and we'll help work out what you have.
