Death Records Rathangan/Duncormick 1840-1901

Catholic parishes rarely kept records of death/burial, I dont see any listed for Rathangan / Duncormick. Civil registration of deaths commenced in 1864 and the (free) IrishGenealogy website includes images on the registers from 1878. Earlier images will be added in time. Research certs can be ordered for earlier records using the index references.

Thank you for your reply.  So to summarize, am I correct in saying that the records of my ancestors' deaths probably don't exist before 1864, but they will all be included somewhere in the registers online starting from 1878?  For example, if I were looking for a Stephen Whelan's death in 1880, and the online website lists 5 of them, can I assume that one of those 5 is the correct one, assuming he stayed in Ireland?  Thank you for your time.

Deaths from 1864 should be registered and included on the index (register images from 1878 at present) but some deaths were not registered so there's no guarantee that there will be a record in all cases. In each case it's a good idea to check all the details of the deaths found for possible matches, particularly the  occupation, reported age (often incorrect), and most importantly the place of death/residence (e.g. townland) and informant - this can be a family member which can help you match to other known details. Deaths which took place away from home or in a hospital or workhouse can be difficult to rule-out or confirm as the informant is generally a staff member and the address will not be the family home.