The postcard with a Christmas message was delivered to the Cradock Street branch of the Swansea Building Society last week, despite being sent in 1903.
Staff are hoping to find the relatives of Lydia Davies to whom the postcard is addressed and deliver this historic postcard to them.
The postcard is addressed to the person addressed as “L” and written by a man named Ewart.
Ewart expresses his regret that he did not receive something that was not labeled “A couple”. He reminds Lydia of her meeting with Gilbert and John and ends the note with “love to all”.
Henry Darby, Swansea Building Society's marketing and communications officer, said he found the postcard while sorting through the mail and that there was limited information online about the recipient of the postcard.
Andrew Dully of the West Glamorgan Archives found that a John F Davies lived at the address with his wife Maria and six children.
A Royal Mail spokesperson said: “This postcard may have been put back into our system. We have an obligation to deliver to the correct address for an item in our system.”
