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10.1. Duplicate Records and Merging

Last Updated 02/17/2026

Merging Scenarios

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Bibliographic catalogers may need to merge duplicate records, or may choose to use the merge function when importing new records or after editing a record in MARCEdit. In all cases, catalogers should follow a set of guidelines to ensure their merges are correct.

When Bibliographic Catalogers discover,or are shown, duplicate records, they should merge those records to help keep the catalog clean and ensure efficient hold fulfillment. Additionally, when importing new records or improving poor records, catalogers may choose to merge new or improved records with existing records, rather than working off the original record.

There are three scenarios that could require merging:

1. You are cataloging a new version of an item with an existing record and need to include information for your current version in the record.
2. An existing record needs to be improved.
3. Multiple records for the same materials exist in the catalog.

In all cases, a bibliographic cataloger should carefully evaluate the record before merging records.

Guidelines for determining when to merge

1. Do not choose a lead record that does not have an OCLC number.
2. If two records have two different OCLC numbers but are discerned to be a good match in most or all other respects, merge the records and append all OCLC numbers from both the lead and sub bibs onto the final, merged bib.
3. If one record has an OCLC number and the second does not, and the ISBNs, titles, and editions match, merge the records.
4. If none of the records have an OCLC number, choose the best as the lead and merge.
5. If the records have the same OCLC number, choose the best as the lead and merge.

NOTE: Make sure you clean up the resulting merged record to comply with current NC Cardinal Best Practices.

Merging and Holds

When merging records, any Title level holds from the deleted record will migrate to the lead record.

Copy level holds and Metarecord holds will remain on the Holds View list for the deleted record. However, they will be actively in the queue for either the designated item (for copy level holds), or any title records still combined in the metarecord. Their holds will be fulfilled in queue order. 

To reduce confusion, you can avoid these lingering holds.

For Copy Holds

Follow the instructions to transfer the holding for the designated copy in the copy hold. The hold will transfer with the holdings. Merge the records as normal.

For Metarecord Holds

The metarecord hold will only show up on the Hold View list for the lead record in the metarecord. Once you have determined that metarecord hold requests are active on one of the records you plan to merge, select that record as the lead record when merging. This will retain all active metarecord hold requests in the Hold View tab of the merged record.