If you require a replacement JU letterbox lock, then Post Boxes UK can help. Simply send an email to [email protected] or call 01922 218218 with the following information: Your name and delivery address We will then forward an invoice to you and upon receipt of payment we can despatch the replacement keys to you same day (for orders before 2pm). Availability - ex-stock. Please note that the JU mailbox lock will only work with JU in front out front (aka front retrieval) post boxes. They will not fit the JU rear retrieval mailboxes. Should you require any further information, please call Post Boxes UK today on +44 (0)1922 218218. Alternatively, your enquiry can be emailed to [email protected] Thank you.