I have composed the following article based on my minimal experience of a year and so of having a credit card with RBC in the hope that you will learn from my mistakes. Please note: there may be more Riba accumulation examples out there.
With regards to the Credit Cards Do’s, all I can say is purchase just about anything except for those I’ve mentioned in the Don’ts.
With regards to the Credit Card Don’ts, all I have to say is, DON’T:
- Pay bills with it if there aren’t authorized payments in intervals(i.e. monthly). As this is seen as a cash advance.
- Make online donations(to some charities, but not all. But don’t take the risk) as this also seen as a cash advance.
- Withdraw money from an ATM with your Credit Card as this is a cash advance.
- Pay your Credit Card payment late as Riba will be charged.
- Pay your Credit Card payment short as Riba will be charged on your entire payment and not on your balance owing.
- Make purchases on new/unknown site as it may be charged as a cash advance. For example, I purchased MuslimKidsTV for my younger siblings, and I got charged the due payment with the addition to Riba because their system retrieves payments like unauthorized bills. An issue that I wrote to them about and Inshallah they resolved on their end.
From my minimal experience, I have shamefully paid Riba on some of these accounts, just because I didn’t know. I remember my first Riba charge of $0.25 and Subhanallah, the pain I felt that day was a different type of pain. Upon that charge, I called my bank to specifically ask what exactly causes Riba to be charged and they Mashallah mentioned some of the points I mentioned, and I had to figure out the rest for myself, the hard way. All I can say is Alhamdulillah, I know better now.
Subhanallah, a few moments ago, I called my bank and this remarkable human being by the name of Michael(may Allah guide or continue to guide him). He informed me that since, I was short $0.14 on my current Credit Card payment that was due a few days ago, according to him would lead me to pay $2 Riba charge on my next Credit Card bill. Subhanallah, through the phone, he probably heard the panic/distress in my voice upon hearing about my future Riba charge and understood that Riba is Haram. As a result, he put a note on my account to credit me the Riba payment a business day after the charge so it would be as if the transaction never happened. Subhanallah, I thanked him repeatedly for this kind, accommodating gesture. Right now, nothing echoes louder than Alhamdulillah in my heart and mind. Alhamdulillah for everything.
Nevertheless, Ya Ummati, learn from my mistake.
Words of a Ramadan Addict 
I prefer using debit cards because I forget to pay bills on time. Michael sounded reasonable, which is rare when dealing with banks.
I was team debit. But now, I just use my visa for all my purchases and just transfer a lump sum from my debit to visa and in the process I get points.
&yeah, Michael was great. I didn’t even have to request it or explain my concern to him. &Because of this occurrence, because of his lovely human behavior, I wish him success in life.