Why isn't Whatsup detecting all of my contacts?

[Windows Central Question]

whatsup contacts

Hi I got Microsoft Lumia and whatsup is not deducting all my contacts. I am sure that my brother has whats up in his android mobile, but it is not deducted.

 

[nicfromwales]

Re: whatsup contacts

If you mean detecting, ask your brother if he can see you in his WhatsApp. If he can, he can message you first.