I have a membership for a service that I have decided to not renew when it is up this month. I was thinking too that I would cancel the subscription a few days before the actual due date as from my experience companies can often mess up the cancellation where you end up getting billed again. Usually the reason can range from there was no one working at the time to process the cancellation or that it takes say three business days to close it from the date of request.
I know this means you technically lose a few days of service, but to me this is more worth it than the potential headache you will get if the company decides to give you the run around. I have even adopted the habit of actually documenting the cancellation process if it is online specific as this way there is no way a business can claim that you didn’t do something right on your end.
I usually find too that even those service where you instruct it to simply not renew can often renew itself anyways. Therefore, best to be prepared either way.