Most numbers at some point have been used before by a company or individual, therefore we put all of our US & UK numbers through a quarantine process.
If any of our numbers receives a call within the first 10 days of us receiving the numbers in from our carriers, they automatically go through into another 30 day quarantine. The numbers will continue round the quarantine process until the number has had 30 consecutive days of no calls. Any numbers continuously receiving calls are returned to our carrier.
This helps us ensure that all of the numbers we provide to our customers are clean and cleansed through our own system.