No — your Foxy credits never expire as long as your account stays active.
How credit retention works
Unused credits stay in your account permanently
They roll over from one billing period to the next
New credits from each billing cycle are added to your existing balance
What happens if you cancel your subscription
Your credits don't disappear when you cancel — they stay safely in your account. However, you'll need an active subscription to spend them. If you cancel, your balance is preserved, but you won't be able to use credits until you resubscribe.
Resubscribing unlocks your saved credits immediately.