1. Introduction
Thank you for choosing the Mitel 5312 IP Telephone. This manual provides essential information for the proper installation, operation, and maintenance of your device. The Mitel 5312 IP Phone is designed for business environments and requires connection to a Mitel Networks 3300 Integrated Communications Platform (ICP), release 3.3 or higher. This product is a renewed item, meaning it has been professionally inspected and tested to work and look like new. It is not suitable for home use.
2. Package Contents
Please verify that all items listed below are included in your package. If any items are missing or damaged, please contact your supplier.
- Mitel 5312 IP Telephone Unit
- Handset
- Handset Coiled Cord
- Ethernet Cable (RJ45)
- Desk Stand / Base

Figure 2.1: Contents of the Mitel 5312 IP Telephone package, including the phone unit, handset, coiled cord, Ethernet cable, and desk stand.
3. Setup and Installation
Follow these steps to set up your Mitel 5312 IP Telephone.
3.1 Attaching the Desk Stand
- Align the tabs on the desk stand with the corresponding slots on the bottom of the telephone unit.
- Gently push the stand into place until it clicks securely.

Figure 3.1: The Mitel 5312 IP Telephone securely placed on its desk stand, ready for connection.
3.2 Connecting the Handset
- Plug one end of the coiled handset cord into the handset.
- Plug the other end of the coiled handset cord into the port labeled with a handset icon on the side of the telephone unit.
3.3 Connecting to the Network (PoE)
The Mitel 5312 IP Telephone is designed to be powered via Power over Ethernet (PoE). A separate power supply is not included and typically not required if your network switch supports PoE.
- Connect one end of the provided Ethernet cable to the LAN port on the back of the telephone unit.
- Connect the other end of the Ethernet cable to a PoE-enabled network switch or a PoE injector.
- The phone will power on automatically and begin the boot-up process. This may take a few moments.
4. Operating Instructions
This section covers the basic functions and features of your Mitel 5312 IP Telephone.

Figure 4.1: Overview of the Mitel 5312 IP Telephone's interface, highlighting the display, programmable feature keys, and numeric keypad.
4.1 Basic Call Functions
- Making a Call: Lift the handset or press the Speaker button. Dial the desired number using the numeric keypad.
- Answering a Call: Lift the handset or press the Speaker button when the phone rings.
- Ending a Call: Replace the handset or press the Speaker button again.
4.2 Keypad and Feature Buttons
The Mitel 5312 features a standard numeric keypad and several dedicated function buttons:
- Programmable Keys: The vertical row of buttons next to the display are programmable keys. Their functions are typically configured by your system administrator and may include speed dials, line appearances, or feature access.
- Volume Control: Use the Up/Down arrows near the display to adjust handset, speaker, or ringer volume.
- Speaker: Toggles the speakerphone on/off.
- Mute: Mutes your microphone during a call. The other party cannot hear you.
- Hold: Places the current call on hold.
- Transfer: Initiates a call transfer.
- Redial: Dials the last number called.
- Message: Accesses your voicemail system. The phone has a digital answering system with 18 minutes recording capacity.
5. Maintenance and Care
Proper care will ensure the longevity and optimal performance of your Mitel 5312 IP Telephone.
- Cleaning: Use a soft, slightly damp cloth to clean the exterior surfaces of the phone. Do not use abrasive cleaners, solvents, or strong chemicals.
- Avoid Liquids: Keep the phone away from liquids and excessive moisture.
- Temperature: Operate the phone within normal office temperature ranges. Avoid extreme heat or cold.
- Handling: Handle the phone with care. Avoid dropping or subjecting it to strong impacts.
6. Troubleshooting
This section addresses common issues you might encounter with your Mitel 5312 IP Telephone.
6.1 No Dial Tone / No Power
- Check Ethernet Cable: Ensure the Ethernet cable is securely connected to both the phone's LAN port and the PoE-enabled network switch/injector.
- Verify PoE: Confirm that the network port you are connected to provides Power over Ethernet. If not, a separate PoE injector or power supply (not included) will be required.
- Network Connectivity: Contact your IT administrator to verify network connectivity and PoE status for your port.
6.2 Buttons Not Responding
- Restart Phone: Disconnect the Ethernet cable for 10 seconds, then reconnect it to restart the phone.
- Clean Buttons: Ensure no debris is lodged around the buttons.
6.3 Poor Call Quality
- Network Congestion: Poor call quality can often be related to network issues. Contact your IT administrator.
- Handset/Cord: Check if the handset cord is securely connected. Try another handset if available to rule out a faulty handset.
For persistent issues or network-related problems, please contact your IT department or system administrator.
7. Specifications
| Feature | Description |
|---|---|
| Model | Mitel 5312 IP Telephone |
| Manufacturer | MITEL |
| Telephone Type | Corded |
| Power Source | Corded Electric (PoE) |
| Dialer Type | Single Keypad |
| Answering System Type | Digital |
| Recording Capacity | 18 Minutes |
| Caller Identification | No |
| UPC | 683193500764 |
| Compatibility | Mitel Networks 3300 Integrated Communications Platform (ICP), release 3.3 or higher |
8. Warranty and Support
As a renewed product, the Mitel 5312 IP Telephone is covered by the Amazon Renewed Guarantee. If you are not satisfied with your purchase, renewed products are eligible for replacement or refund under this guarantee.
For technical support related to the phone's integration with your network or PBX system, please contact your organization's IT department or your Mitel service provider.





