Do unused credits roll over to next month?

Yes. Unused credits stay in your balance when your plan renews. At each renewal, Rendair adds your monthly credits on top of what you already have. It does not reset the balance to zero. Credits you buy as top-ups also stay in your balance.

This means you can save credits in a quiet month and use them in a busy one.

Example: you are on Starter with 500 credits a month and you use 300 in your first month. At renewal you have 200 left plus 500 new credits, so 700 in total.

If you cancel

Credits left in your balance stay in your account after you cancel. Your account moves to the Free plan.