Do you need to be careful with magnets around your credit/debit/other cards?
The short answer is the same as it's been for the last couple of decades...yes!
The longer answer is...it depends. Newer cards issued by banks and other places, like hotels and loyalty programs, are moving more and more to embedded chip technologies which are far more resilient to magnetic fields.
Our advice will always be to keep a few inches between your credit cards and any magnet, including those used in MAGFAST products. In practice, you'll probably find that modern cards, the kind you 'dip' rather than swipe, will often survive accidental magnetic co-habitation. Exposure time often determines whether a card gets demagnetized.
Also, keep your credit cards protected. Using credit card protection sleeves or proper wallet storage will help to keep the magnetic strips on your credit cards safe.