If there are duplicate Person Accounts, it would be best to merge them together for better record keeping.
MAKE POTENTIAL DUPLICATES VISIBLE
First, you have to make sure that the Potential Duplicate card is available on the page layout. This way, when you open the Account, it will show the number of potential duplicates for the account.
If not available, follow the steps below:
1. On the Person Account record page, click on the Settings icon at the top-right corner. Click on Edit Page.
2. Click and drag Potential Duplicate to your desired location on the page. Go to Display Options and choose whether you want to show a Toast ( pop-up alert) or Card or both. Click Save.
ACTIVATE MATCHING AND DUPLICATE RULES
1. Go to Setup. Enter Duplicate Rule on the Quick Find box and click on Matching Rules under Data.
Make sure a Matching Rule has been set up for duplicate Person Accounts and that it is active. ( As shown below)
2. Go back to Setup and choose Duplicate Rules. Create a New Rule for Standard Person Account Duplicate Rule. (see image for information). Activate Rule.
MERGE PERSON ACCOUNTS
1. Go to a Person Account record page. Check on Potential Duplicates under Related Tab. Click on View Duplicates.
2. Select the Person Accounts you want to merge and click Next. You can choose up to 3 Accounts.
3. Choose which account you want to use as the Master Account and which values you want to use for the merged account. Click Next.
4. Confirm Merge. Take note that merging of accounts cannot be undone.
Attached Financial Accounts or Financial Account goals and any other custom object records will be carried over to the merged account.
All Related Household accounts will also be added to the merged account.