Yes, you can upgrade or downgrade your plan at any time from your account settings under “Subscription.” Changes take effect according to your current billing cycle.
What happens to your credits:
When downgrading, you won't lose credits immediately, but your credit cap will shrink next month. If your balance exceeds the new plan's cap (3x monthly allocation) on renewal, you'll stop receiving new credits until your balance drops below that limit.
When upgrading, your credit cap increases to 3x your new monthly plan amount, allowing you to accumulate more credits.
Best practice: Spend or export excess credits before your new billing cycle begins to avoid hitting the cap when downgrading.