Yes, you can upgrade at any time. When you upgrade to a monthly or annual Pro plan, any remaining coins from your current plan will be converted into a credit and applied toward the cost of your new plan.
How it works: We calculate your upgrade credit based on your remaining unused coins using the following formula:
(Remaining Coins ÷ Monthly Coin Allotment) × Price of Current Plan = Your Upgrade Credit
Your new Pro plan billing cycle and full coin allowance will take effect immediately upon upgrade.