I forgot my wallet and must pay for a repair. I think I recall the Visa number but would like to verify somehow prior to having it declined at the shop. (So I can make the drive to get it before instead of after.)

However, I am leery of typing my number into any old web service. I can’t call my bank because what I need to pay for is the repair of the phone!

I do remember the CVV, but of course I don’t have the code to check it against the card number. (Besides, the computer I’d run it on is with the wallet.)

Is there a safe solution that is easier than just driving for an hour to fetch the wallet?

I tried to create CVV as a tag but I must not have enough rep.

  • 3
    Almost all credit cards numbers can be validated as real credit card numbers using the Luhn Algorithm. It is not full-proof and will just tell you if the number could be valid, but it supposedly handles common errors pretty well, like swapping two digits besides 0 and 9. (See the section on strengths and weaknesses for more details)
    – clcto
    Commented Sep 21, 2018 at 16:58
  • But I don’t just need “it’s a valid number,” rather it is correctly my number, I.e., the CVV works.
    – WGroleau
    Commented Sep 21, 2018 at 17:44
  • This algorithm is worth trying, though, if this happens again. My issue was whether I had swapped the second four with the third four.
    – WGroleau
    Commented Sep 21, 2018 at 18:04
  • @clcto The expression is "fool-proof". Commented Sep 21, 2018 at 18:56

1 Answer 1


Regarding calling the bank, it seems you need a phone, not your phone. Even the repair shop might let you use their phone.

Since you somehow have web access, is there an online merchant you are accustomed to purchasing from, where you could order something small you might want anyway, or buy a gift card? After entering the card number you remember, you can confirm that the order succeeds.

  • I tried to think of something I needed, but couldn’t. Then I asked a friend nearby if I could buy something for her, and she couldn’t think of anything either. Finally, I bought a cheap gift for someone. :-)
    – WGroleau
    Commented Sep 21, 2018 at 17:46
  • Had to use a shop I hadn’t used before, since most of the few I’ve used would just re-use the same card.
    – WGroleau
    Commented Sep 21, 2018 at 18:05
  • @WGroleau Even if a site has your card saved, you could still enter it as a one-time "new" card.
    – nanoman
    Commented Sep 21, 2018 at 18:23
  • @WGroleau If you use incognito mode, the website wouldn't have access to the cookies, so it should make you enter the number again. Also, I think most websites throw an error if you try to buy something with an invalid card before you confirm the purchase. Commented Sep 21, 2018 at 19:00
  • @Acccumulation: true. or I could use tor. Anyway, it turns out I did remember the number.
    – WGroleau
    Commented Sep 21, 2018 at 20:51

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