I have had my card blocked at home only rarely. One occasion comes to mind - I had bought something fairly large online late at night. No sooner had I clicked Purchase than my phone rang - the bank was asking had I actually just spent [$amount] at [$online store]? I said yes and that was that. A little later I made another purchase late at night on a different card. It went through, but when I tried to use the card the next day for something small in a store, it was declined. Embarrassed, I used a different card then called the bank. They said they had put the card on hold because of the online purchase for a large amount, even though they had let the purchase go through. They hadn't called me because it was late at night, and they hadn't given themselves any reasonable mechanisms to compensate for that (like calling me the next morning, emailing me, or the like) they'd just blocked the card. We had what you might call a frank and open exchange of views on the matter.
Not all banks use the same strategies or software. I suggest:
- try to know your banks foibles. If large online purchases may be an issue, try to do that during business hours when they can call you, for example
- have more than one card. Do the "suspicious" stuff on a different card than the one you like to buy groceries with. Or simply have another card you can pull out when the first is declined
- call your bank after every decline - to learn more about why, and to let them know they are providing bad customer service in their attempts to prevent fraud. They can't tweak their algorithm if they don't know it's failing.
- learn which of your cards is the touchiest, and decide how you feel about partitioning your regular spend with that knowledge. Some people will use it the most, so that it knows you best and is less likely to decline. Some people will use it the least, so as not to reward touchiness with revenue. Make a deliberate decision
Far and away the simplest thing is just to have more than one card so that these declines are a momentary hiccup you might forget by the time you and your Rolex are out of the store.