Is there still an issue that many places only take NETS? This caused me to fall back on cash (or the card of someone with me) more than once.

Yeah, @KateGregory is correct. PayWave is far from ubiquitous. Many places do not accept foreign cards. If you want to be sure of paying everywhere in Singapore you need a PayNow compatible wallet. I use GrabPay. And some cash too.

@MJeffryes Foreignness doesn't come into it, some places just don't want to pay credit card fees. But they're mostly in the heartlands, in the central, touristy bits of Singapore aside from hawkers/street markets CC acceptance is nearly 100%.

Foreignness doesn't come into it This is false. I have a foreign card and occasionally run into trouble using it in Singapore. For example, you can't top up your EZ-Link card using a foreign card (though they now say that from Dec 2024 onwards, this will be possible but with a hefty 3.5% admin fee). Foreign cards also frequently fail on online payments.

@user103496 For online payments, it's probably your own (foreign) bank rejecting the transaction due to fraud concerns, not the Singaporean merchant.

The local merchants/payment systems may also only accept local addresses, postal codes in the local format (6 digit), or phone numbers in the local format (8 digit). If your card details don't match those, then you can't use your card.

Email from one merchant: "our system currently only accepts Singapore addresses". Email from another: "NETS has rejected the transaction".

@lambshaanxy You are wrong. Singapore has a domestic payment network NETS. Many merchants have only a NETS terminal, presumably because the fees are lower than those charged by Visa or Mastercard.

@MJeffryes I lived in Singapore for ten years and am well aware of this fact. NETS is a debit system, not credit card. As a tourist, you don't need to care about this, just carry cash as a backup.

NETS is a debit system, not credit card. As a tourist, you don't need to care about this Again, yet another falsehood. NETS processes many credit card payments and does routinely reject foreign credit cards, as per my comment above. Wikipedia: The nationwide acceptance infrastructure is the largest in Singapore and includes 54,000 Unified Point-of-Sale (Unified POS) terminals (which accept NETS, NETS FlashPay, debit and credit cards such as VISA, Mastercard, American Express, UnionPay, RuPay and JCB) and 94,000 QR acceptance points (for payments via NETSPay, PayLah!, Pay Anyone and Mighty).

@user103496 When Singaporeans refer to paying by "NETS", they always mean "NETS Debit", not various merchant services provided by the Network for Electronic Payments (Singapore) Pte Ltd.

@lambshaanxy In that case, you probably don't understand that foreign debit and credit cards cannot be processed through a NETS terminal. You are wrong when you said that this is not about foreignness, you are wrong when you said this is an issue with the issuing bank, but for some reason you are stubbornly unable to accept this. Of course tourists need to worry about this because it is precisely the topic of the question. Foreign cards do not work in NETS terminals! Get a foreign card, try and use it with a NETS terminal then report back.

@MJeffryes Now I think you're the confused one? A standard NETS POS terminal accepts only NETS (debit) cards and does not accept any credit cards, Singaporean or foreign: nets.com.sg/nets/for-business/nets-pos

@lambshaanxy When did I say it accepts credit cards?

@MJeffryes When did I claim a NETS terminal accepts foreign cards?

@lambshaanxy You said 'foreignness doesn't come into it'. And later said it was due to a foreign bank stopping transactions. When in fact the NETS network accepts domestic debit cards and rejects foreign ones.

@MJeffryes OP was asking about credit cards.

@lambshaanxy You're just being evasive now. You said some places prefer only to accept debit cards. In reality they only accept domestic debit cards. Your answer did not cover the fact that many places where locals can by card (or with their banking app by NETS QR code) will require a foreigner pays with cash, which is an important and confusing (to tourists) aspect of payment in Singapore. Me and Kate helpfully pointed this out, and for some reason you've chosen to pick a fight. But I see you've now edited your answer to incorporate this, so thank you.