If you upgrade your plan, the new plan will be activated immediately. The fee will be prorated based on the price difference and the remaining days in your billing cycle, and it will be included in your current invoice.
Example:
If you start a 30-day billing cycle with a $5,00 plan and upgrade to a $15,00 plan on the 15th day, your total charge will be:
$5,00+($15,00-$5,00)*(15/30)=$10,00.