The Yealink T4 series includes professional business IP desk phones designed for users handling moderate to high call volumes. These devices offer HD audio, programmable line keys, and flexible wired and wireless connectivity options.
Supported Models & Firmware
The following Yealink T4 series models are supported:
- T48U
- T48G
- T46U
- T43U
- T42U — Requires firmware 108.84.0.30 or later*
*Note: Only the models with required firmware versions have listed specifications.
Key Features
- Colour Displays – High-resolution LCD screens for improved visibility and call management.
- Programmable Line Keys – Multiple programmable line and feature keys for efficient call handling.
- HD Audio – Wideband voice quality ensures clear, professional conversations.
- USB Connectivity – Dual USB ports (U models) support Bluetooth dongles, Wi-Fi adapters, USB headsets, and storage devices.
- Headset Support – Compatible with USB and RJ-9 wired headsets, as well as optional EHS wireless headset adapters.
- Gigabit Ethernet Ports – Dual Ethernet ports with PoE support for reliable network performance.
- On-Device Conferencing – Supports 3-way conferencing directly from the desk phone.
- Optional Wi-Fi Support – Compatible with Yealink Wi-Fi adapters for flexible deployment.
Yealink T46U Button Guide
The diagram below shows the layout of a Yealink SIP-T46U desk phone.
- Line Keys – Select a line, monitor calls, or access assigned features.
- Soft Keys – Context-sensitive buttons aligned with on-screen options.
- Navigator Key – Scroll and confirm menu selections using directional arrows and the OK button.
- Mute Key – Toggle microphone audio on or off.
- Hold Key – Place or retrieve a call on hold.
- Transfer Key – Perform attended (warm) transfers.
- Speaker Key – Enable or disable speakerphone mode.
- Headset Key – Activate a connected headset.
- Voicemail Key – Access voicemail messages.
- Redial Key – Redial the most recent number.
- Volume Keys – Adjust ringer or speaker volume.
- Dial Pad – Standard 12-key keypad for dialling and character input.
Yealink T43U Button Guide
The diagram below shows the layout of a Yealink SIP-T43U desk phone.
- Line Keys – Select a line, monitor calls, or access assigned features.
- Soft Keys – Context-sensitive buttons aligned with on-screen options.
- Navigator Key – Scroll and confirm menu selections.
- Mute Key – Toggle microphone audio on or off.
- Headset Key – Activate a connected headset.
- Voicemail Key – Access voicemail messages.
- Redial Key – Redial the most recent number.
- Speaker Key – Enable or disable speakerphone mode.
- Volume Keys – Adjust ringer or speaker volume.
- Dial Pad – Standard 12-key keypad for dialling and character input.
Yealink EXP43 T4U Series Expansion Module
The Yealink EXP43 expansion module adds additional programmable line keys for users who require expanded call monitoring and directory access.
- 4.3" 272 × 480-pixel colour display
- 20 programmable keys per page with dual-colour LEDs
- Three illuminated page-switch keys
- Supports up to 3 modules in a daisy-chain configuration
- Stand with two adjustable angles
- Compatible only with T43U and T46U models
Compatible wall mount
The Yealink WMB-T46 wall mount is compatible with T43U and T46U desk phone models.
Official resources
For full technical specifications and additional documentation, refer to the official Yealink data sheets for your specific T4 series model.