"Could not set up Apple Pay, an error occurred while setting up Apple Pay"

None of these suggestions helped or addressed the problem. I can't get past the "add card" step without an error message. So I can't even enter card info.

I had the same problem and solved it.

1. go to Settings>General>Language & Region
2. Change your region.
3. Click on the prompt "Change to..." whatever region you chose.
4. Once you change your region, change it again to your region... "United States" in my case.

I went back to the walled application and was able to add my cards.

I hope this works for you.

Cant set up Apple Pay

1. Sometimes if you sign out of your Apple ID and back in it resolves the problem.
2. Check your Apple ID region to make sure it is correct. If it is correct, you may need to select the same region again. (Change your Apple ID country or region - Apple Support)
3. Check the region on your device to ensure it is correct (Settings>general>language & region - set to your region)
4. A passcode is required to use the Wallet app. 
5. You need to be in a region that supports Apple Pay - Countries and regions that support Apple Pay - Apple Support
6. Your bank needs to support Apple Pay - Apple Pay participating banks - Apple Support
7. If none of these suggestions are able to resolve your issue you can go here for further assistance - If you can't add cards to Wallet for Apple Pay - Apple Support

• If you need to change your default payment in Wallet or have other issues such as the inability to add passes you can go to these links which covers managing Wallet and wallet use.
• Add and manage passes in Wallet on iPhone - Apple Support, please note that passes cannot be directly added within wallet, except for QR code enabled passes. For everything else, its done either through the associated app, an email, airdrop or a link in a website.
• If you get an error that you already have the maximum amount of cards in wallet with less than 22 cards signing out of your Apple ID and back in usually resolves this issue.
• If you are getting a message to contact the card issuer, call the bank or credit card company who issued you the card to make sure there are no restrictions on the card. 
• If you are getting a message that Apple Pay services are unavailable at this time, sign out of your Apple ID and back in.
• How to use Wallet on your iPhone, iPod touch, and Apple Watch - Apple Support,
• Manage the cards that you use with Apple Pay - Apple Support

Tried all these steps. Apple Pay was working on phone and was reestablished after sign out/sign in routine, but gives error when setting up any card or Apple Cash on watch.

I had a second watch on my account (lost) that did have Apple Pay setup (but apparently disabled in “lost” mode) and I removed the watch from account with no change ...

Well I never!!!! Read this whole thread few times and has done the change region and restart merry go round mor thins that I can remember. Then carefully re-read your post Askbarnabus and it WORKED. The devil is in the detail. Clicking the picture initiated the apple pay add process. It like it can’t add a card until it is initialised I.e. by clicking the picture. You’re a legend. I’ve been faffing around with this for weeks! THANK YOU!

Changing region works a treat if you’re having problems adding cards to your wallet on your phone . BUT , then when you wish to add these cards then to your Apple Watch, it gives me this message every time! I have tried just about everything. I even deleted the watch and paired it again because I thought I did something wrong whilst setting up. NOPE!

also tried many others: changing region, logging out/into of iCloud, turning off/on passcode, re-adding cards a million times, Checking other random things in settings etc. STILL WILL NOT WORK!

cards are visible in Apple Watch app but when I go to add them, I get error message every time

Got it fixed! Just change your region to somewhere else and change back to USA, done!

I solved this by clicking on the country in Region again.

I have iPhone 12 pro with iOS 14.3.

Go to Settings > Language & Region > Region > I just clicked on United States again. The phone started setting up region, though it was already set to United States.

After that I went to Settings > Wallet & Apple Pay > Add Card, this time it worked perfectly.

Hope this helps.

Nothings working I’m getting very frustrated with this I’m trying to add a card and all options I know failed

Sorry to hear a_ukboy. Perhaps our problems are different. I was getting the message when I pressed (touched) the "+" in the wallet app to add any card. You seem to be able to get to the point of trying to add the card (AMEX). I was not able to go that far until I did what I described before.

I suppose you spoke with AMEX about it. Maybe other AMEX customers have had the same problem.

I wish I could be more help. I'd like to know how you solve the problem once you do.

Best of luck.

doesn't work for me, i tried all the suggested things but no good. i actually lost the few cards i had stored in there and now cannot add any.

Oh lucky you! To have at least one card linked!

I cannot link my MasterCard or visa card !

it’s making me all kinds of crazy

wish apple would help

I’m still having this issue, it’s only on my Apple Watch and only with my Amex card, I can set up fine with my visa and MasterCard, I’ve tried everything, signing in and out of iCloud, reset watch, changed region, spoken to Amex, nothing works, so frustrating!!

works absolutely fine with my phone, just my watch, driving me nuts!!!!

it was working fine, but I wanted to create an iCloud email address, it wouldn’t allow me and the fix was to sign out and back in to iCloud, got my email address but of course it signs out all the cards with Apple Pay, and since unable to set up the Amex with Apple Watch!

Thanks Mromeu for the reply, but that hasn’t worked for me, it’s only an issue with my American Express card, works fine on my phone but unable to set it up on my watch, have had the card replaced and I still get the error message with setting up the new card too