WhatsApp Customer Service Number Cleaning: From E.164 Format and Deduplication to Activation Check and CRM Write-Back

Before importing a customer service list into the WhatsApp channel or CRM, clean it in this order: keep original values, convert to E.164, deduplicate by canonical number, check activation by country, and write back in groups. The article explains the special encoding for Argentina and Mexico, why an empty privacy field does not mean inactive, and how to write results back to the CRM.