The main long-term repository for ING data (from the WHT, INT and JKT) is the data archive at CASU in Cambridge, UK (ING Archive).

In addition, ING maintains a local engineering archive (accessible to staff only) which currently holds a copy of all WHT and INT data taken after 18 July 2011. The engineering archive is used e.g. for quality control and troubleshooting, and when PIs request a copy of mislaid data.

Data from WEAVE, the multi-object spectrograph at the WHT, will be stored in a dedicated data archive (hosted by TNG on La Palma).WEAVE data will also be copied to the ING's local engineering archive, but not to the CASU archive.

During the era of WEAVE, observations from non-WEAVE instruments will continue to be copied to the CASU archive and to ING's local engineering archive.

Observing logs
Digital observing logs back to January 1993 can be obtained (if more than a year old) by querying the logs archive. Prior to 1993, observations were logged in A3 paper logbooks, currently stored at ING.

For an individual exposure, most of the information given in the corresponding line of the observing log is reproduced in the FITS headers of the raw data.