With sipgate you can easily block unwanted calls in your accounts Blocklist settings.
When you're logged in to your account (Admins & Users) you'll find the option "Blocklist" in the Navigation bar.
On clicking Blocklist a new screen will come up, giving you the option to blocklist unwanted calls.
Click the ADD NUMBER TO BLOCKLIST button.
A further pop-up window appears, where you have the option to manually add phone numbers you want to blocklist. You can also block phone numbers which start with the first few digits of the number just entered.
To complete the action, the click the blue ADD NUMBER TO BLOCKLIST button again.
After saving the unwanted phone numbers, any calls from these blocked numbers won't ring any User on your account. The numbers will now show up listed in your Blocklist settings.
To unblock a phone number again, please click on the "3 dots" icon at the end of the row and choose delete. Calls from that number will then ring users on your account again.
The "3 dots" icon also allows you to edit the already blocklisted phone numbers in the list. Clicking the edit option will open the pop-up window and allow you to carry out changes. Once done, click the SAVE CHANGES button.
Your phone or device may also have call screening and blocklisting options available.
You can also register your number with the TPS:
The Telephone Preference Service (TPS) is the official, freely available UK central opt out register on which you can record your preference not to receive unsolicited sales or marketing calls:
As TPS registration only prevents marketing calls, organisations will still be able to call you for the purposes of genuine market research.