Last spring when I cycled in Portugal I picked up a data-only sim card from a Portuguese company. Next spring I will be starting in Madrid then making my way to Portugal so will require a data-only sim card that works in both. From what I understand, all EU sim cards work all over the EU. Is this correct? What are others' findings with Spain + Portugal sim cards? What were you happy with? Vodafone? Orange? Movistar? Other?

Thanks.

We bought an Orange sim for our three months in Spain earlier this year.  It worked well and was affordable but I am sure the other service providers would also be OK.

In early October, I got a prepaid 28 day 40 GB SIM card from Movistar for 10 euros.  They offered me extra GB when it was time to renew. Coverage in Spain was terrific. It also came with 200 minutes calling time to anywhere in the world.   One thing to remember - you need your passport to get the SIM card.

Great price. Do you know if it would work in other EU countries?

Hmm.  I've tried to reply, and have somehow failed.  Will try again.   Yes, the card is good for roaming in the EU and UK.  And you get even more GB now for your 10 euros.  There are other options too.   Look for pre-paid options on the movistar website.  Chrome translation worked for me.

movistar page. Filter by 'prepaid'.

Keith and I are back from 2 months in Spain and Portugal and used Airalo Electronic SIM cards. They were great and incredibly inexpensive. There was the huge advantage of buying them before we left home, simply turning off our physical SIMS on the plane and turning on the electronic SIM when we landed. You can also buy a regional SIM which is good for 39 European countries. We chose to buy just Spain and Portugal as we knew we would only be in those two countries. I just checked their app, as an example 10 GB of data for 30 days in Portugal is $17 US. 10 GB of data in the Eurozone for 30 days is $37 US. Pretty darn reasonable. The only caveat is that your phone has to be new enough to support eSIM. We each had three SIM cards on our phones, home, which was turned off until we landed back in Canada, one for Portugal and one for Spain. You turn on the one you want to use in settings. Google Airalo and there is lots of information. 

Thank you for the info. Unfortunately, my device is not esim compatible. Looking at Airalo's site it appears to me they are only esim.

As Hamlet said, there’s the rub. Our phones are newer so we were able to use esims. You are quite right, Airalo is esim only. 

Movistar seems to beat Airalo by far?

We bought a Lycamobile SIM in England - 15 pounds for 30 gB, doled out as 1 gB limit daily. Now I see that that amount of money for the first time buys unlimited data from them, in UK anyway. I had assumed that with Brexit the SIM would either not work in Europe, or would be slower or limited. But no, it carried on just as in UK. I had earlier thought to activate my German Vodaphone SIM once we ferried to Dieppe, but Lyca was lots cheaper. Lyca is currently  keeping my SIM alive with no usage, a year for 5 pounds.

By the way, our one year old Mexican Telcel SIMs are still alive. 500 pesos ($25) gives 6 gB per month, not so great, but it does work seamlessly in Canada and US too. Also, you can get unlimited calling for a month plus 3 gB for 200 pesos.

That sounds like a great deal.  Those prices highlight just how badly we are ripped off in Canada by carriers.   For travel I did love the convenience of buying the esims at home and activating on arrival, and doing it in English.