If you are making update request for large number of entries, or many changes of features/locations/qualifiers due to sequence modification, see followings.

(1) Update information is in common of all entries.
Example: change reference or submitters information, postpone the hold-date, etc..

In principle, send your request via Application Form for Data Update Requests

(2) Contents of corrections are different among entries.
Example: change each clone or gene name of all entries, etc..
(3) Extensive correction of data
Example: change more than 30 features due to the sequence update, etc..

In case of (2) or (3), we would like to know the number of entries, the correction item, etc. to specify the file format for your request.
Contact us in advance from contact form.
In general, we handle update requests within several days but for a large number of entries, it might take us time in updating the data.
Be sure to contact us beforehand when you request the release of data which accompanies correction.