Does Custom Mapping overwrite existing data?

[Perc-BRC]

Thanks. Trying to finish up docs for clients, wanted to be sure but couldn't remember

[CnP.Support.AM]

Good day @Perc-BRC

Yes, it overwrites the info based on the mapping.

[Perc-BRC]

Hi- I seem to see this behavior, but it's not confirmed anywhere in documentation-- does custom mapping overwrite existing data on existing contact/accounts? I know Alias info doesn't ever overwrite, but wanted to confirm the mapping does. Thanks!