USB-C to RJ9 Adapter StarTech UR9-HEADSET-ADAPTER for Office Phone Handset/Headset

The StarTech USB-C to RJ9 Adapter (UR9-HEADSET-ADAPTER) provides a direct connection between devices with a USB-C audio-capable port and RJ9 handset or headset jacks on office desk phones. Designed to enable audio routing for calls and unified communications, the adapter allows a computer or compatible USB-C endpoint to send and receive audio through a phone’s handset/headset port without modifying the phone hardware. The compact adapter supports standard telephony headset interfaces and is intended for professional environments where interoperability between modern endpoints and legacy desk phones is required.

Advantages

This adapter offers a straightforward plug-and-play solution for integrating USB-C devices with traditional RJ9 headset/handset ports. It preserves the desk phone’s physical connection while allowing audio from a USB-C device to be used for calls and conferencing. The product’s small form factor and single-cable connection minimize workspace clutter and simplify setup. Compatibility with USB-C audio endpoints removes the need for additional converters or phone alterations.

Suitable for

• Office workers using unified communications applications on a laptop or desktop with USB-C audio
• Customer support and call center agents who need to use computer audio through existing desk phone headsets
• IT departments implementing hybrid setups that combine modern endpoints with legacy phone systems
• Conference rooms where a USB-C meeting device must interface with a desk phone headset

Key specifications

• Connector types: USB-C (audio-capable host) to RJ9 (handset/headset)
• Audio direction: bidirectional audio routing between USB-C endpoint and RJ9 headset/handset port
• Form factor: compact inline adapter for desk use
• Compatibility: designed for office desk phones with RJ9 headset/handset jacks and USB-C audio-capable devices
• Power: draws power from the USB-C host (no external power required)

How to use

Connect the USB-C plug to a USB-C audio-capable port on your computer or compatible endpoint. Insert the RJ9 connector into the handset or headset jack on the desk phone. Once connected, configure the audio input/output settings on the computer or unified communications application to use the USB-C audio device if necessary. The adapter routes audio between the two devices and allows the desk phone headset or handset to carry the computer’s call audio without altering phone wiring.

Usage recommendations

Verify that the host device supports USB-C audio before use. Test audio routing and adjust system audio settings to ensure correct input and output selection. For best results in professional environments, combine the adapter with headsets and phones that adhere to standard RJ9 wiring and impedance specifications.