The function overlayCount allows you to check how many numbers you are using, have used in the past, or will use in the future. Regular snapshots are taken of overlay usage and the closest applicable value will be shown if you request a historical value. Predictions for the future are based on current expiry times for overlay, working on the assumption that you will make no more overlay requests. You can also use this function to see how your number usage has changed over a time period.
Check how many numbers have been used over the last week: