Just pay it before statement is cut.
Even If you pay interest, it will not be much on small balance.
It is not back interest like a store card.
The bank calculates an average daily balance during the period. Since your balance is on an increasing trend, it’s somewhere in between the prior statement balance and the latest statement balance.
The amount is an approximation of how interest is being calculated. The actual interest calculation is on a compounded daily rate, based on each day balance, but that may be too much info.
Finally I found a perfect picture explaining almost everything. The only question I have -- if I do not pay off the full balance to zero at the second orange Payment Due Date, but only the 2nd statement balance, and thus I stay owed $200, what is the difference? Will interest be accrued on that $200 right after I paid the 2nd statement balance?
And in other sources, I found information that if I do not pay the previous bill in full, then interest begins to accrue not from the due date, but from the very beginning of the billing cycle, which contradicts this picture above.
If you have a $200 balance when interest starts, a 20% APR will begin calculating interest at $0.001 per day. One tenth of a cent per day, or about $4 per month if you left it there. I think you should leave the $200 balance so you can see the interest at work. We can try to explain it, but no explanation gives the same educational quality as actual experience. A small balance experience is the way to go.
The discussion so so far has been about promotional interest periods. On credit cards, this usually means interest only begins after the expiration of the promo period. You have added comments asking about Deferred Interest. The most common example is a furniture store that sells on a long term zero interest “plan”. If you do not pay every last dime of the furniture cost ( or whatever you bought ) by the end of the Deferred Interest period, all ( ALL! ) that Deferred Interest is reassessed for the entire time you thought you were getting zero interest cost. Nasty.
