Just one more WhatsApp tip, which I was reminded of by a friend currently walking who was having a bit of WhatsApp mix-up.
WhatsApp only works with mobile numbers, and all mobile numbers in Spain either begin with a 6 (more common) or 7 (more recently introduced). Land lines begin with a 9 (more common) or an 8 (more recently introduced).
That means there’s no point in inputting (is that a word?) a number that’s a land line. If you put in a mobile number, WhatsApp will tell you whether it uses WhatsApp or not. If they don’t, WhatsApp gives you the opportunity to ask send them a message and ask them if they would like to use it. But in the case of Spanish numbers, I think that in the case of any Spanish mobile phone that doesn’t use WhatsApp, it’s is because the owner very consciously has decided that he or she doesn’t want to use WhatsApp. So then the option is to call.