Credit cards in Spain.
 

None of those. I regularly used my Costco VISA (no foreign exchange fees) that has no pin. No problem, not in taxis, restaurants, supermarkets, hotel, etc.
Used Amex in one hotel.

I have a US card with tap capability. Even at the very same store (here in Germany) sometimes it works perfectly well when tapping, and sometimes the tap is denied. Then the cashier usually says, "try it again", and I'll insert it, and then it works. I've never had to enter a pin for a credit card, but you need it for a debit card in an ATM to withdraw money. Usually machines both read chips and accept taps - - and also have a groove to run a magnetic stripe - - but this is subject to exceptions, and to change. You're always best off getting the most recent technology if you can.

No chip or pin needed but one thing you need to watch out for (especially in Spain) is the DCC currency conversion they almost always offer. If you have a no-transaction fee credit card, which you should get if you don't already have, always decline the "offer" to convert to US dollars. You need to be very clear and pay attention that they don't hit that dollar button without asking you.

If you have an iPhone, load your cards in the Wallet to use with Apple Pay. That works at any terminal that accepts contactless payments. I live in Europe but have a few cards issued by US banks that are still Chip + Signature, which is a pain when store clerks are expecting a pin.

I recently had an overnight layover in Oslo. When I checked out of the hotel the next morning, the clerk presented the price in both NOK and USD. I told her to charge me in NOK and she told me it's the same. It's possible she really believed that, but it wasn't true. I know it wasn't true because when I looked at my statement later, I saw that the USD price shown by the hotel would have been 10% more than the NOK charge that posted to my account. That's a nice bonus for the merchant but not good for you. Insist on being charged in euros and don't believe them if they say it's the same.

I think the bank gets the cut, or maybe they split it, I’m not sure.. even Ryanair “offers” to perform this difficult task of converting to dollars for you, but they show exactly what you will pay.. yet some people still do it! It’s robbery in plain sight.

Sometimes when I use my US Visa card in Germany they turn the machine over to me and I have to click left or right to decide if I want to pay in Dollars or Euro. I always choose Euro since the card claims to charge no conversion fee. But using the same card other retail establishments on identical-looking machines (with tap, chip, and slide functions) I don't get the option.

In Spain, credit cards are generally chip-enabled and require a PIN to be used for in-person transactions. Tap-enabled cards are also becoming more common, but not all merchants may accept them yet. The number of digits on a credit card varies depending on the card issuer, but most commonly they have 16 digits. It's always a good idea to inform your credit card issuer of your travel plans before leaving your home country to avoid any issues with card usage while abroad.

I use credit cards in Spain all the time, I have never had to use a pin, ever. Last week I was there for a work related visit and the only card I had to insert was my business credit card which is not "tappable." But all my personal cards are accepted by tapping, no problem... maybe Spanish issued credit cards are different, but for me, never had to put in a pin number. Signature on the other hand can be required.

I think the reason some people accept charges in USD is because they like the idea of knowing exactly what they are paying. But if they would do the math, they would see what a rip off it is. The credit card company will give you a far better exchange rate than the merchant.

In Spain, most credit cards are chip-enabled and require a PIN to complete transactions. Contactless (tap) payments are also widely accepted, and many credit cards in Spain now come with this feature.

The chip technology provides enhanced security for credit card transactions by generating a unique code for each transaction, which makes it more difficult for fraudsters to clone a card. Additionally, the use of a PIN provides an added layer of protection against unauthorized transactions.i am also using credit cards

Most credit cards in Spain have a 4-digit PIN, although some may have a 6-digit PIN. However, it's important to note that the exact requirements for credit cards in Spain may vary depending on the issuer, so it's always a good idea to check with your bank or credit card company before traveling to ensure that your card is compatible and will work smoothly during your trip.
<!--td {border: 1px solid #cccccc;}br {mso-data-placement:same-cell;}-->

As I think I mentioned already, above, I just returned from 2-weeks+ in Spain and used my credit card(s) all the time. Almost never used cash, in fact, even taxis took the cards. My main card does not have a PIN and that was not once a problem. Sometimes I used the tap function, too. Everytime I was in a restaurant, I was presented with the option of USD or EUR when the person taking the charge would turn the cc machine towards me. Of course, I selected EUR for payment. There was never any problem using a non-PIN card. However, I never used a gas station (diesel gets so much mileage to the liter!!! I drove and drove and drove and returned the car with half a tank full). So maybe a gas station or toll booth might be an issue; I've no idea about that but would like to know, for next time.

I've been to Spain a couple of times and at least 30 other trips to Europe. I've never, in any part of Europe, had trouble using a credit card for not having a PIN. IME this is a non-issue.

Thanks
 

Thanks to all. Looks like we will be fine. Safe and happy travels to all.

Side question ...
Are there any bank's ATM machines that do not charge pricey ATM use fees?

I used a Caixa Bank ATM last month and it clearly stated that there was a 7% fee for the withdrawal. I wonder about the opinions here of this bank. I agreed to the charge but in retrospect, should not have done so, and should have gone to Santander or another bank. I failed to do much reserach on ATMs beforoe I left, although I've made about 50 trips to Europe over the years.

My last trip I could not find an ATM machine that did not post that I would be charged a fee . If I remember right it was around 2.95 Euro to 4.95 Euro.
It is not my bank as they do not charge for out of network ATM machines. Plus I have used the same bank in many other countries and when I found an ATM machine that did not have a fee, my bank charged me just the amount I withdrawal.
Another fun fact ... In almost all cases I got charged less using my ATM card then when I would exchange a similar amount of cash.
I think if you use your bank to withdrawal there would be no charges.
But since you say you withdrawal money from an ATM fee free, do you mind sharing what bank does a no fee. I will be there later this month and would like to find these fee free ATM machines.
"had an ATM charge me a pricey ATM use fee."
Maybe we have different ideas what is pricey. For me 2.95 to more then 6 is pricey.
"suspect the problem is your own bank"
I can assure you that if the Spanish ATM machine (or any other country) has no fee ,my bank charges no fees. I pay just what the exchange rate is with no extra fees. I am sure other banks might charge a fee, but mine does not.

Comicman my experience is the same as yours, around the same fee per transaction. But I have a Schwab account that refunds those fees at the end of the month. I’m not opposed to a 3 or 4 euro fee, as long as the conversion is done correctly.