My advice to anyone searching the GRO indexes is to search all available sites and compare them. Note the differences in page numbers.
Name: WILLS, ELLEN MAUD mother's maiden name: -
GRO Reference: 1876 S Quarter in KINGSBRIDGE Volume 05B Page 208 Occasional Copy: A
Surname First name(s) District Vol Page
Births Sep 1876 (>99%)
WILLS Ellen Maud Kingsbridge 5b 208a
Name: Ellen Maud Wills
Registration Year: 1876
Registration Quarter: Jul-Aug-Sep
Registration district: Kingsbridge
Inferred County: Devon
FreeBMD and Ancestry both give us access to the images of the printed GRO index. FreeBMD is double-keyed by two transcribers; we don't know how Ancestry has generated their index. Here are snips of the two pages.
Even though sites have "the same" index, there can be variations between sites in any part of the data. Always compare when you can.
Update: @TomH reminds me that Ancestry's data comes from FreeBMD.
Here is his comment:
Actually the Ancestry index for records prior to 1915 is the FreeBMD
index (look at the title of the record set) but it's an old snapshot
so doesn't have more recent corrections.
It is true that Ancestry used to have FreeBMD referenced in the title of the database, but in the USA, they seem to have deprecated those databases, and republished the data without referencing FreeBMD in the title. The information I quoted is from dbid=8912, now titled England & Wales, Civil Registration Birth Index, 1837-1915. However, you can tell this is a snapshot of FreeBMD by looking at the source information:
FreeBMD. England & Wales, Civil Registration Birth Index, 1837-1915
[database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2006.
Original data: General Register Office. England and Wales Civil
Registration Indexes. London, England: General Register Office. ©
Crown copyright. Published by permission of the Controller of HMSO and
the Office for National Statistics. You must not copy on, transfer or
reproduce records without the prior permission of ONS. Database
Copyright © 1998-2003 Graham Hart, Ben Laurie, Camilla von Massenbach
and David Mayall.
His main point is absolutely correct -- whenever Ancestry incorporates an index from another website, such as FreeBMD, Find a Grave, or any index marked Web: in the Card Catalog, it is only a snapshot of that site's index at a single moment in time. According to Crista Cowan, anything marked Web: in the card catalog is not updated by Ancestry, so for the most recent version of the data, go directly to the original site and re-run the search there for the most current version of the data. Where images are also provided, the image quality for different sites can vary as well.