CallWithUs and Save! Low rate SIP and calling card calls
Effective Aug 1st 2021 several UK communication providers have announced origin based charging to surcharge internationally originated calls to UK numbers or calls to UK numbers that have missing, malformed or Fake CLI's. You can lookup the surcharge table, the surcharge per minute amount depends on your caller id country and the type of UK number you're calling (fixed or mobile).
Your caller id number must be in E.164 format (staring with +country_code). We will allow calls to UK numbers if your caller id number belongs to a country with a 0 surcharge rate OR you explicitly enable "Allow UK Surcharge" parameter in "user settings" menu in customer portal, it is set to "no" by default.
Complete rate lists can be downloaded in csv format: Standard (last updated: September 21 2021), Premium (last updated: September 21 2021), PSTN (last updated: September 21 2021), per trunk (last updated: September 21 2021)