I get confused with reviews writing "minimum spend" when the bank website does not specify the minimum. What does it do actually? Does it waive off annual fees?

Hi depends on the context. Firstly, theres no minimum spend to use a credit card. However, there may be minimum spend to unlock certain benefits.

1. Minimum spend on Credit Card to get cashback/more cashback. Since your question tagged 'POSB Everyday Card', I shall use that as an example.

• On POSB website, it states 'Get UP TO 15% cash rebates'. Woah, wonderful. But its definitely a 'bait' for you to sign up blindly if you dont read the TnCs carefully.
• The truth is, there is only 0.3% cashback for ALL SPEND. With exclusions, of course. You cant get cashback for certain govt services, AXS services, ezlink, etc.
• The 15% cashback is only for DINE catergory (Online Food Delivery and Online Food Catering). And thats not all, there's a minimum monthly target to spend before you can unlock 15%. So if you order total only 1 GrabFood order $20 in 1 month, you will only get 0.3%

2. As per what you have mentioned, all Credit Cards have annual fees. There are conditions to get it wavied. Mainly, you need to use the card frequent enough. So some bank may set certain minimum amount to spend per year to wavie annual fees.

But I suppose most people are more concerned with point 1. Point 2, if they dont waive, you can simply cancel the card.