Phone number format and your default country
Why WhatsApp needs the full international number, and how Vatli reads numbers that arrive without a country code.
WhatsApp identifies people by their full international number — country code plus national number. Getting this right is the single most important thing about your contact list.
The rule
- Best: store numbers as
+[country code][number], e.g.+919876543210(India) or+14155550123(US). Spaces and dashes are fine; Vatli normalises them. - Works if your default country is set:
9876543210— Vatli adds your default country code. - Never guessed: a number that already has a country code is never changed.
Set your default country
- Go to Settings → WhatsApp (for manual connections, open Enter credentials manually).
- Pick Default country for phone numbers — the country most of your contacts are in.
- Save.
The default country is used only when a number arrives without a country code — from a website form, a CSV, the API or a CRM that stores the local format. If a number isn’t valid in your default country either, Vatli flags it instead of sending, so a message never reaches the wrong person.
Why so careful? Measured on real data, hundreds of Indian 10-digit numbers also form valid US numbers. A wrong guess doesn’t fail — it messages a stranger. Vatli only guesses when the result can be checked.
Numbers that are valid but not on WhatsApp
A correctly formatted mobile number isn’t necessarily a WhatsApp account. Sends to those numbers come back as 131026 — Message undeliverable. That’s not a fault in your list or in Vatli. See Why a message failed.