Hey,

WhatsApp (also WhatsApp Business) merely imports contacts from your phone's native Contacts app. Therefore, the initial step is to change your PST contacts into VCF format. The most reliable way is through a correct PST to VCF converter that keeps every aspect of mobile numbers, office numbers, labels, and notes intact. CSV or online tools often change the details of the contacts, particularly if a contact has several phone numbers.

The method that worked perfectly for me:

Load your PST inside a professional converter.

Confirm all contacts appear correctly in the preview.

Select Convert PST to vCard to export VCF files.

Import those VCF files into your phones Contacts app.

WhatsApp Business automatically syncs them.

I used WholeClear PST to VCF Converter, and it exported everything accurately. For anyone who needs a reliable PST to vCard converter, especially for WhatsApp Business migrations, this method is the cleanest and fastest.