A .eu domain will enter Quarantine if no payment has been made on or before the due date of renewal. The domain enters Quarantine the day after the due date.
Unfortunately there is no grace period given with .eu domains. The cost to remove a domain from Quarantine is €40 + VAT.
If you have any questions on the above, please do not hesitate to 'Open a Ticket' and we will be happy to advise further.