I had a plan with 500 minutes and I realized I had 31 dollars in overtime. I switched to a plan with unlimited minutes because I, clearly, need more than 500. I have 6 days left on my billing cycle. When will the unlimited minutes come in effect?
Your unlimited minutes becomes effective today and moving forward. The prorating of minutes will mean you had only about 24/30ths of your minutes, or about 400 minutes for the portion of the month you had the plan, and you will be charged overage for 100 minutes in addition to the 62 excess minutes you have already consumed.
The new plan takes effect immediately after choosing it. Keep in mind that choosing a plan with more or unlimited minutes won't negate that overage you accumulated prior to the plan change and could be more due to proration.
So just an FYI For those who will be using more minutes than their plan and want to avoid pro-ration due to a plan change as it may shoot themselves in the foot with more overage charges. I suggest you purchase the $20 unlimited callingn add-on. Once you reach the end of your billing cycle, you are safer to switch to a plan that is more suitable for your needs