Natural deaths had/have to be registered within five days. In cases of accidental death, the coroner would have to be informed and an inquest held. This would have taken only a matter of days, so the only way the registration would take place in a different year would be if the accident took place at the very end of one year and the registration at the very beginning of the next.
The death certificates will show the precise date and place of the deaths, as well as their cause. Make sure you buy them direct from the GRO (
www.gro.gov.uk). Third parties will try and rip you off for considerably more than the statutory £9.25 fee.
Caroline