Every account has one wallet. You add credit when you want, you pay only when a resource actually runs, and any unused balance is refundable. There is no monthly subscription tied to the account itself.
Top-ups start at EUR 5,00. The balance is shown in your account header and ticks down per-minute as resources accrue charges. We email you well before the balance hits zero, so a credit shortage never silently stops your apps.
Why a wallet, not a subscription
It maps to how you actually use the platform: spin up extra capacity for a launch, scale back between launches, pay only for the time something ran. A monthly subscription would charge you the same whether your app was idle or under load.