There are times when you may want to prevent your phone number from appearing on the recipient’s device. When this feature is active, the party you are dialing will see "Private," "Unknown," or "Withheld" instead of your number.
How to Withhold Your Number
1. Temporarily (Call-by-Call)
To hide your number for a single specific call:
Dial *67 followed by the phone number (e.g.,
*670123456789).The recipient will not see your number for this call only.
2. Permanently (Account-wide)
If you wish to hide your Caller ID for all outbound calls by default:
Please email our team at support@onsim.uk to request this change.
Common Use Cases
Privacy: Preventing personal or direct-dial numbers from being stored in a recipient's call history.
Credit Control: Used by finance departments to reach individuals regarding outstanding balances without the call being screened.
Confidentiality: Essential for sensitive services where the caller's identity or location must remain protected.
Important Considerations
[!IMPORTANT] Answer Rates: Many people choose not to answer calls from "Unknown" numbers as a matter of personal or security policy.
Abuse & Traceability: Withholding your number does not make you anonymous to the network. In cases of harassment or abuse, calls can still be traced back to the source. OnSim maintains a zero-tolerance policy regarding the use of our platform for harassment; misuse may lead to service termination and potential legal action.
An Alternative Solution: Generic Numbers
If you are concerned that your number is being recognized and avoided, withholding your ID may not be the best solution, as it can look suspicious.
Instead, we can provide a secondary generic number.
How it works: We assign an additional geographic or non-geographic number to your account. You can then use this as your "outbound identity" so the recipient sees a valid, recognizable number that isn't your primary line.
Cost: £1 + VAT per month.
Note: Changing your outbound ID is a manual process managed by our support team.