What is small balance adjustment? It's a well-kept small secret in the credit card business. If your credit card balance at statement date is a very small amount, the issuer will usually add a credit of the same amount so your statement will show no balance to pay for.
I personally experienced this at both Providian and FirstUSA/BankOne for three times when I closed month with a balance of $0.25 to $0.51. Why did I encounter such a small balance? I usually test a new card by driving to a self-serve gas station (is there a better place to test whether a new card is working?) and making a gas purchase of a quarter or two. Every time, I found the respective issuer gave me a credit at statement date to adjust the balance to zero.
Why do issuers want to do you such a favor? I googled a lot but there is very little information on this topic. My guess is the cost to handle a payment is comparatively higher than the small change waived. Imagine if you send out a check of $0.51, the issuer needs to staff warm bodies to open the envelope, scan your account number and put the amount into the system, not to mention a banking fee to clear your check. But on the other hand, leaving even a $0.01 balance opened the door for late payment penalties and default APRs, so issuers may not be worse off to keep the small balance in the statement. Maybe these issuers know I am diligent in tracking money and making timely payments, so there is no chance to earn such penalties from me, but I doubt issuers keep different small balanace adjustment policies with people of different credit profiles.
I'm hesitate to think this as another avenue to save month. After all, even if I have 20 dormant cards and I can pocket $0.50 small balance adjustment per card per month, it's only $10 per month. Every $0.50 will take around one minute for gas refilling, and two or three minutes for online tracking, so the payoff is still low at $10/hour.
Do you have any experience with small balance adjustment?