According to the information I found, while Vapi allows importing UK numbers, there might be configuration issues preventing it from appearing in the tool section. Try verifying that the number is properly imported and formatted in E.164 format (with country code). Check your Twilio settings if you imported through Twilio, ensuring the webhook URL is correctly pointing to the Vapi endpoint.
Sources:
- [Troubleshooting steps for UK numbers not showing up as configured numbers in Vapi](
https://discord.com/channels/1211482211119796234/1340004417448968292)
- [What are the requirements for a phone number to be considered a 'configured number' in Vapi?](
https://docs.vapi.ai/phone-calling)