Keeping track of 64-8s

When new clients join us, we normally note on an excel sheet the date 64-8 is sent to HMRC. We note the date which falls 14 days after this date on the excel sheet and check the website on that day to see if we have been authorized. If not, we check the website again the following day and so on.

When there are several clients joining every week, we need to keep track of the day when we need to check for several clients. It has become quite time consuming to keep track of this 14 day period and managing the list of clients. We wanted to see if there is any software out there that can help us in this task? Also how do we know if any of the clients on our list has moved on to another accountant, assuming we do not receive any letters from the new accountant or the client? We would like to hear from practitioners, as well as software providers.

Thanks.