What are the main network providers in Spain? Who has the best network coverage? What tariffs are available? For instance here in UK I have a sim only plan 20g data, unlimited calls, messages for £20 monthly which is ample. Are there similar deals with networks in Spain?

I´m not an expert on mobile phone packages, but if you have a look on this website it seems they do a package for ten euros a month and another for 20 euros.

https://o2online.es/movil/

The only networks in Spain are Movistar, Vodafone and Orange - everyone piggy-backs off one of these.

The big thing is to make sure you can pick up one of these signals and then choose the best company for your needs.

For example, we can't get good Vodafone signals here and Orange is hit-n-miss

Yes there are similar deals - look at SUOP.es or even Lobster if you call the UK a lot

Thanks for posting that, it's very useful to see it in writing.

Thanks for the website, very good site.

You forgot Yoigo.

Unfortunately sometimes the only way to find out which of those 4 has the best coverage where you need it is to buy a one off prepaid SIM from each and try them for yourself.

You are correct - they recently went away from MasMovil (ish)