I was going through some old paperwork recently, and I found some old bank cards that had expired. It’s good practice to destroy expired cards, so that the numbers on them can’t be used for identity theft.
The normal way to destroy a card is to shred it. If you want to go one step better, you can try erasing the numbers from the card entirely. I found quite a fun way to do this, using nothing but things I found in my kitchen. Here’s what I did:
I boiled a kettle, filled a mug with boiling water, then I dropped my card in it. I saw the raised plastic numbers dissolve almost instantly, and soon after, the plastic film on which the numbers are actually printed came away as well. After five minutes, the EMV chip fell out as well. I poked and prodded at it with some cutlery — I don’t think this helps with the security, but it was fun to see how weirdly I could bend the card. (Several cards had four or five folds.)
Once I was done, I fished it out and ran it under the cold tap to harden the plastic. Then I chopped it into small pieces, and scattered them across several bins.
This doesn’t make it impossible for somebody to read the numbers from my card, but it makes it quite a bit harder. (I can still make out very faint outlines, but I know what numbers used to be there — I don’t know if somebody else could read them.) Overall, I’m calling that a win.