If the cause of death is sudden or unnatural a coroner may need to carry out a post-mortem or inquest. The coroner usually carries out the post-mortem 2 to 3 working days after the death. But the reports can take weeks, even months to be finished. Keep this in mind as it may delay registering the death. This is because you’ll only receive the documents you need to register the death once the coroner’s reports have been done.