There is a pretty well known “trick,” where if you apply for more than one credit card from the same bank, on the same day, you could potentially get hit with only one credit pull. This is important, because ~10% of your credit score is based on how many inquiries you have on your credit report. The idea is that banks are less likely to extend you credit if you are constantly asking for it.
Many banks have now put in measures to prevent that from happening. For example, while many credit inquiries used to not show up on your report until the next day, they are now reporting faster. Additionally, some banks simply prohibiting you from applying for more than one cards a day. Still others pull a new report for each application.
Intentional or not, there are still banks that allow you to “consolidate” credit inquiries. And reddit user RideRide2 took it to the next (many) levels. S/he applied for 24 cards on the same day, and got approved for all of them under ONE hard pull (i.e. credit inquiry).
Needless to say, this attracted a little bit of attention from Bank of America. In fact, one of the cards got frozen before it could even be used. You can read more about RideRide2’s story, including how s/he went about meeting minimum spending requirements to get the sign-up bonuses on Reddit.
I’m definitely filing this under “do not try this at home.” If it doesn’t go as planned, you could end up with a ton of new hard pulls on your credit report, and of course the bank can always cancel the cards.