The majority of the Council's older archives were at one time stored in Oswestry Library, which until 1959 was based in the town's municipal buildings, the Guildhall. Others, and more recent records, were in the Powis Hall. In 1985-9, all the archives were brought together in the Guildhall. The Town Council took the decision to keep all the records in Oswestry and to apply for it to become a recognised place of deposit. An air-conditioned strong room was installed, search room facilities were provided for in the public rooms, a conservation programme was set up and a part-time archivist appointed to catalogue the archives. The Guildhall was appointed a place of deposit in 1989 under the Public Records Act 1958.

In 1999, following a successful application for a grant from the Heritage Lottery Fund, the Guildhall was renovated for Council and community use. An additional room was equipped for storage of archives and improved search room facilities were provided. The catalogue of the archives was published to mark the re-opening of the building.

In 2010 the archive strongrooms were refurbished to increase the storage capacity and to update the equipment that regulates the carefully controlled environment needed to store documents.