Thousands of birth and death records have been found to be missing from the General Register Office (GRO) online indexes, according to Lost Cousins founder Peter Calver.
The indexes were introduced in November 2016 and list the 1837-1917 birth records and 1837-1957 death records held by the GRO.
The new civil registration indexes have been welcomed by family historians because, unlike the historic printed GRO indexes, which are available on a number of websites, the new indexes enable researchers to verify mother's maiden name on birth records and age at death on death records going back to the start of civil registration in 1837.
However, Peter Calver, founder of the Lost Cousins website and newsletter, explained in his 9 November newsletter that he'd investigated missing birth records following a complaint from a reader.
He compared them to FreeBMD, a website run by the charity Free UK Genealogy which has published its own transcriptions of the GRO's original printed indexes.
Mr Calver found that over 7,000 birth entries from volume 4A of the July-September quarter of 1881 had been duplicated in volume 3B, whilst over 5,000 entries that should have appeared in 3B were missing.
In a second newsletter from 12 November, he reported that readers had highlighted three other missing record sets.
There were up to 11,000 births missing from volume 11A in the October-December quarter of 1902.
In the final quarter of 1860, 4,000 birth entries were missing from volume 6C and had been replaced by 3,000 duplicated entries from volume 4B in the April-June quarter.
About 2,000 death records from volume 1C in the January-March quarter of 1863 were gone, and had been replaced by 4,500 records from volume 2C.
Readers also reported that when they'd complained about the missing records, the GRO had told them that their query had been investigated but no amendment was required.
Mr Calver told Who Do You Think You Are? Magazine: "Whilst the fact that the errors occurred in the first place is understandable, the way that the queries were handled isn't."
He called on the GRO to compare the new indexes against the FreeBMD records.
This would be possible because Free UK Genealogy has confirmed that it will make the data freely available under an Open Data licence.
He also recommended allowing a more flexible searching of the GRO indexes, which currently require searchers to specify the correct surname.
A spokesperson for the Home Office, which runs the GRO website, said: "We welcome potential errors or omissions in our online index being brought to our attention and have a process in place to ensure that the details are corrected.
"Customers should be reassured that any issue with entries in the online index will not prevent them from ordering certificates from the General Register Office where they have identified the index reference number from another source."
Rosemary Collins is the staff writer of Who Do You Think You Are? Magazine
