The answer depends on how you want to use your business number. OnSim offers two distinct ways to handle your calls, depending on whether you just need to receive calls or if you also need to make them.
Option 1: Virtual Landline (Inbound Only)
No, you do not need to switch providers. With a Virtual Landline, your business number simply acts as a "pointer." When a customer calls your 01, 02, or 03 number, we instantly divert that call to your existing mobile (on EE, O2, Vodafone, etc.).
Keep your current SIM: No changes are made to your existing mobile contract.
Keep your personal number: You still receive personal calls as normal.
Crystal Clear: Because it uses the standard voice network, the quality is perfect.
Option 2: Landline SIM (Inbound & Outbound)
If you want to display your landline number when calling customers back, you will need to use an OnSim SIM or eSIM.
To make outbound calls showing your landline ID, you have two choices:
Dual SIM: Keep your current provider and add an OnSim eSIM as a second line on your phone (requires a compatible handset).
Full Switch: Upgrade to our Landline SIM service and port your current mobile number over to us. This replaces your current provider entirely and gives you full office features on one SIM.
Which one is right for you?
| Feature | Virtual Landline | Landline SIM |
|---|---|---|
| Receive Landline Calls | ✅ | ✅ |
| Make Calls showing Landline ID | ❌ | ✅ |
| Keep Current Mobile Provider | ✅ | Optional (via Dual SIM) |
| Professional Features (Hold/Transfer) | ❌ | ✅ |