Merge duplicate contacts or accounts

Two account records for Acme Energy and four contact records for Jamie Rodriguez exist; the reps complain the history is split. Merge the two Acme accounts into the one with the most complete billing address and retain the parent account ID 0045-ACM. For contacts, merge the four Jamie Rodriguez contacts into the record with the most recent opportunity activity, preserve all email addresses and notes, and transfer open tasks and open opportunities to the consolidated contact. Keep the older but verified phone number. Notify account owner Maria Chen and include a changelog of fields overwritten.

Before I merge these duplicates, make it obvious what a reviewer would lose or gain. Show side-by-side the two Acme accounts’ opportunity pipelines, open tasks, and active users; flag any conflicting billing or tax IDs. For the Jamie Rodriguez candidates, surface which contact has most recent activity, which has the verified phone and which holds longer historical notes. Highlight any linked contracts that would change owner after a merge and flag those for legal review.

I just attempted to merge two Acme accounts and now a major opportunity that was on Alice Park's forecast is missing from the consolidated record. I don't know which pre-merge account held it or whether it's recoverable. Diagnose the likely place the opportunity went, the fastest safe recovery step, and how to prevent this from happening on future merges so we don't lose forecasted revenue.

Across the quarter we keep merging duplicates but lose call logs, campaign responses, and parts of the opportunity history, which frustrates reps and skews reporting. Where are we making the same merge decisions that cost us history, and what single merge policy or tool change would preserve activity and stop the cleanup backlog?