If your account balance is negative, this is most likely because you didn’t have enough money in your business account to cover your monthly subscription fee.
Your monthly subscription fee is deducted from your Revolut business account balance. The funds will be deducted from your default currency account, which you can find and edit in the Settings tab. All you need to do is top up your account via bank transfer to keep using your business account. If you forget to top up, we may charge the card linked to your account.