The 5420 supports the following features:

• High-end feature set with productivity local call log and speed dial directory.
• Advanced user interface.
• Reduced installation and move costs, no paper labels.
• Investment protection with downloadable firmware.
• Large screen 7 line x 29 character display.
• 24 Programmable call appearance/feature keys (arranged in 3 switchable display pages of 8 matching the 8 physical display buttons).
• Adjustable desk stand.
• Fully global ready (Icons used to indicate fixed button functionality).
• Large message waiting indicator.
• Headset jack.
• 9 fixed feature keys below the display.
• 7 navigation keys (4 soft, 3 fixed).
• Language customisation (choice of languages for local phone menu).
• Eight personalized Ring Patterns.
• Desk or wall mountable.
• Connects to an IP Office DS (Digital Station) port.