This article explains the correct and recommended way to add new contacts, update existing ones, or delete a portion of your contacts without the need to delete the entire data source.
It's common for your contact database to grow, be updated, or for you to want to delete some users.
Therefore, there's no need to import new complementary files, nor to delete the old ones. You can update and complete existing data.
Additionally, remember that you have a maximum number of data sources, depending on your subscription, so you may want to update a single existing file rather than importing multiple files.
How to do this? From 'Add data source,' if you select CSV or Copy-paste, we'll recommend updating existing data as the first option."
You will also have the 'Upload new version' option available if you access any of your imported CSV files.
The new file must have the same column format as the original one. It won't be possible to add new fields.
We will utilize the Key Field from the original file (in this example, the phone number) to detect modifications: contacts added, deleted, or updated. Select the new file, or copy-paste the new data.
Click continue and follow the steps, to configure what to do with the new data provided.
Confirm your selection and decide whether to add a tag to the new contacts and if you want to modify the tag for the old contacts.
In a few minutes, your .CSV with your contacts will have been updated.