Spreadsheets
How to Format International Phone Numbers for CSV Uploads
By WaSenderHQ Editorial Team•2026-07-27•4 min read
Phone number formatting errors are the single most common cause of failed WhatsApp message dispatches. Understanding international numbering standards ensures 100% queue execution accuracy.
International Number Syntax
WhatsApp requires phone numbers to include country call prefixes without leading zeroes, plus signs, brackets, or dashes. For example, a US number should be formatted as 15551234567, and a UK number as 447123456789.
Excel Formula for Quick Formatting
If your spreadsheet contains spaces or dashes, use Excel's SUBSTITUTE formula to clean numbers instantly: =SUBSTITUTE(SUBSTITUTE(A2,"-","")," ","").