At 17:11 Gradwell Engineers were alerted to customers experiencing inbound call failures with the behaviour “Number Invalid”. Gradwell Engineers were fully engaged on the incident which was given a priority one status.
Our engineers identified the inbound call failures only affected a subset of numbers through a certain range holder and contacted the upstream supplier for further investigation. This was resolved at 17:37.
The root cause was due to a manual task completed by the upstream supplier where they had inadvertently applied the changes to a wider range of numbers than was intended.
They have a process which is designed to prevent manual errors such as this, but unfortunately, this was down to a human error.
They have taken steps to reinforce the process which will eradicate a considerable number of manual steps in the process which will ensure far less risk going forward.
Please accept Gradwell’s apologies for the loss of services and the impact it has had to your business.