
Yealink T42S
The Yealink SIP-T42S VoIP Desk phone is the successor of the Yealink SIP-T42P. It introduces new features and improved audio quality. The IP phone from this line is a high-performance professional tool. It provides superior quality voice connections and has more extensive parameters.
Featuring a large 2.7-inch LCD display, 6 programmable buttons, 2 Gigabit Ethernet ports and a USB 2.0 port, it is ideal for intensive daily use. It can perform auto-provisioning, auto-configuration and auto-update. The T-42S is an easy-to-use telephone that proves to be perfect for business needs.
Key Features
Yealink T42S Advanced Call Management
The Yealink SIP-T42S Desk phone is the successor of the popular Yealink SIP-T42s. It has a number of improvements and new features. Among other things, this phone supports 12 SIP accounts instead of 3, and the sound clarity is much better. With its 2.7-inch (192x64p) LCD display, all essential information can be read at a glance.
Your partner’s voice is always clear and natural thanks to the Opus codec. Its role is to improve the sound of the device. Opus codecs offer superior HD audio quality compared to other systems. The Yealink T42S is also hearing aid compatible (HAC). This makes it accessible to everyone, including people with hearing loss.

A reliable IP phone for your business
The Yealink T42S is a professional phone with a large graphic LCD screen capable of managing 3 SIP accounts. Its particularity is to provide 6 function keys with LEDs. It is suitable for companies looking for an easily manageable phone as it has fully automatic provisioning, configuration, and update functions. The Yealink T42S offers all essential telephony features:
- Caller name
- Number identification
- Call transfer
- 3-way conferencing
- Internal communication
- And much more
Technical properties
- IP phone, SIP protocol
- 12 configurable SIP accounts
- Large 2.7″ graphic LCD display
- 4 navigation keys
- 6 programmable keys with LEDs
- EHS: support for automatic release via wireless headset
- HD Voice: HD cordec for high quality sound
- 2 x 10/100/1000M Gigabit Ethernet ports
- Hearing aid compatible handset
- USB 2.0 port
- Full duplex handsfree
- Self-powered PoE: Power over Ethernet cable
- Wall mounting possible
- Advanced call management: call waiting, conference, transfer…
- Multi languages
- Opus Codec Support
- Power supply not included
Product specifics
- SIP 2.0 (RFC3261)
- TI TITAN Chip
- Compatible with VLAN and QoS
- In-band DTMF and out-of-band numbering RFC 2833 DMTF
- Proxy mode and peer-to-peer SIP mode
- HD Codecs: G722
- VoIP Codes: G.711, G723.1, G726, G729A/B
Integration and security aspects
- Enterprise directory (XML, LDAP)
- Compatible with XML development
- SRTP/TLS/HTTPS compatible, AES encryption
- TLS (Transport Layer Security) compatible
- Compatible with VLAN (802.1 pq) configuration, QoS
- Adjustable configuration mode: administrator/user
Model | SIP-T42S |
LCD | 2.7″ graphical LCD |
Resolution | 192 x 64 |
LCD Backlight | √ |
Line | 12 |
PoE | √ |
GigE | √ |
Wall Mounting | √ |
Foot Stand | 2 adjustable angles |
USB Port (2.0 compliant) | 1 |
Ethernet Port | Dual-port Gigabit Ethernet |
Handset Port (RJ-9) | √ |
Headset Port (RJ-9) | √ |
External Yealink AC Adapter (optional) | AC 100~240V input and DC 5V/1.2A output |
Line Key | 6 |
Memory Key | 15 (3 pages of 5 keys) |
Yealink EXP50 Expansion Module (Accessory, purchased separately) |
X |
Yealink EXP40 Expansion Module (Accessory, purchased separately) |
x |
Yealink EXP20 Expansion Module (Accessory, purchased separately) |
X |
Yealink EHS36 Wireless Headset Adapter (Accessory, purchased separately) |
√ |
Yealink YHS32 Headset (Accessory, purchased separately) |
√ |
Yealink Bluetooth Adapter BT40 (Accessory, purchased separately) |
√ |
Yealink Wi-Fi Adapter WF40 (Accessory, purchased separately) |
√ |
USB Recording | √ |
3-way Conferencing | √ |
HD Voice | HD Speaker HD Handset |
Wide-band Codecs | G.722, Opus |
Narrow-band Codecs | G.711(A/µ), G.729, G729A, G.726, G.723.1, iLBC, Opus |
LCD Type | Fixed |
Operating System | Linux |
Built-in Bluetooth | X |
Built-in Wi-Fi | X |
USB Headset (Accessory, purchased separately) |
√ |
Camera | X |
Video Resolution | X |
Video Codecs | X |
3-way Video Conferencing | X |
5-way video/audio mixed conferencing | X |
HDMI | X |

Yealink T42S adapts to your environment
Yealink T42S is compatible with SIP environments:
- Alcatel-Lucent
- Aastra
- Avaya
- 3CX
- Asterisk
- Sipleo
You can choose between PoE power and conventional power supply. The supplied Ethernet cable allows the terminal to be powered by PoE. For a conventional power supply, you can purchase a power supply unit separately.
YEALINK T42S FOCUS ON YOUR CONVERSATION
Get the most out of your conversations with the T42S and Yealink audio performance. With its Full Duplex HD quality, you’ll hear the person you’re talking to as if he or she was sitting next to you. In the same way, you’ll be perfectly heard by your callers. The communication will be efficient, clear, and pleasant.
You have all your devices at your disposal with the WIFI and Bluetooth connections integrated into the device. This allows you to move freely in your workplace while always being connected.