Does anyone have a suggestion on a rental phone for 7 days on the Sarria to Santiago section. We will probably only use it for calling a taxi or the hotel if need be. Not for calling the U.S.
Check with your cell provider. I know with Sprint, international roaming is only 19 cents a minute, so for the limited amount of time you’d need it, or use it, it may not pay to try and find a rental.
Rick Steve's advice may be helpful.
Bad-Value Options: Many car-rental companies, mobile-phone companies, and even some hotels offer the option to rent a mobile phone with a European number. This is a terrible value, as hidden fees (such as high per-minute charges) can add up.
Get a sim card for your phone. There is free wifi in every cafe, bar and hotel on the Camino. People in the cafes, etc. will call a taxi for you if you ask.
Do not rent a phone. Heck you can buy a BIC phone for about 20€.
First, will your current phone work in Spain, and at what cost per minute? Even if it's $2 per minute, it's cheapest and easiest to just use what you have if you're only making a few calls of short duration. And, as said, T-Mobile and Sprint are usually much cheaper than this (20-25 cents per minute, and free on Wi-Fi if your phone works with Wi-Fi calling).
If your current phone won't work in Spain, you can buy a basic model for less than you can rent one. Just go into any phone store in Spain.
Since you say "we," even if your phone won't work in Spain, check with your co-travelers - someone's is bound to.