With most companies if you have 1,000 credits per month and only used up 300 then you'd lose the other 700 when the month reset.
We prefer to give you those credits. If you only used up 300 of 1000 this month, you'd have 1,700 next month. You don't need to panic to finish off existing credits.
How do credits work?
If you have not read it, see how credits work: http://help.anymailfinder.com/basics/how-do-credits-work