(Theoretical) Paying credit cards with other credit cards
If you had a CC issuer that allowed you to do bill-pay this way, I suspect the payment would be considered a cash advance that will trigger a fee and a pretty egregious cash advance specific interest rate.  It's not normal for a credit payment portal to accept a credit card as payment. If you were able to do this as a balance transfer, again there would be fees to transfer the balance and you would not earn any rewards from the transferred balance.  I think it's important to note that cash back benefits are effectively paid by merchant fees.  You make a $100 charge, the merchant pays about $2.50 in transaction fee, you're credited with about $1 of cash back (or points or whatever).  Absent a merchant transaction and the associated fee there's no pot of money from which to apply cash back rewards. Three things prevent you from doing this: Credit cards generally don't accept other credit cards as payment.  You could do this with a cash advance or balance transfer, but Cash advances and balance transfers usually have fees associated with them, negating any reward you might earn. Your card might have a no-fee balance transfer promotion going, but Cash advances and balance transfers generally aren't eligible for rewards. "A ""balance transfer"" is paying one credit card with another.  You probably get offers in the mail to do this all of the time.  As other posters have noted, however, this usually comes with finance fees rather than the rewards that you get for normal purchases because it's written into your credit card agreement as a different class of transaction with different rules. I'm not sure if it's urban legend or true, but I have heard stories that suggest there were some ""loop holes"" in the earliest credit card reward plans that allowed for something like what you want.  I doubt that any plan ever allowed exactly what you've written, but I've heard stories about people buying gift cards from merchants and then using the gift cards to pay their bill.  This loop hole (if it ever existed) is closed now, but it would have allowed for essentially infinite generation of rewards at no cost to the cardholder.  The banks and credit card companies have a lot of years of experience at this sort of thing now, so the threshold for you finding something that works and conforms with the cardholder agreement is pretty small."
The whole point of a credit report and, by extension, a credit score, is to demonstrate (and judge) your ability to repay borrowed funds.  Everything stems from that goal; available credit, payment history, collections, etc all serve to demonstrate whether or not you personally are a good investment for lenders to pursue. Revolving credit balances are tricky because they are more complicated than fixed loans (for the rest of this answer, I'll just talk about credit cards, though it also applies to lines of credit such as overdraft protection for checking accounts, HELOCs, and other such products). Having a large available balance relative to your income means that at any time you could suddenly drown yourself in debt.  Having no credit cards means you don't have experience managing them (and personal finances are governed largely by behavior, meaning experience is invaluable).  Having credit cards but carrying a high balance means you know how to borrow money, but not pay it back.  Having credit cards but carrying no balance means you don't know how to borrow money (or you don't trust yourself to pay it back). Ideally, lenders will see a pattern of you borrowing a portion of the available credit, and then paying it down.  Generally that means utilizing up to 30% of your available credit.  Even if you maintain the balance in that range without paying it off completely, it at least shows that you have restraint, and are able to stop spending at a limit you personally set, rather than the limit the bank sets for you. So, to answer your question, 0% balance on your credit cards is bad because you might as well not have them.  Use it, pay it off, rinse and repeat, and it will demonstrate your ability to exercise self control as well as your ability to repay your debts. "A credit card is basically a ""revolving"" loan, in which you're allowed to borrow up to a certain amount (the limit), and any time you borrow, you pay interest.  If you were to *borrow* $100 to pay for something via a credit card, you'd have a $100 balance on the card. If you then pay $70 cash to the card, there would be $30 remaining.  That $30 balance could accrue interest. The timing of that interest charge could vary. The 20% you've quoted is almost certainly ""APR,"" of which the ""A"" stands for ""annual,"" so that 20% would be an annual rate.  It makes the most sense, mind you, to keep a minimal balance on a credit card, as the interest rate is higher than most other loans." Good credit is calculated (by many lenders) by taking your FICO score which is calculated based upon what is in your credit report.  Building credit generally means building up your FICO score. Your FICO score is impacted my many factors, one small one of which is your utilization ratio of your installment loans like student loans.  This is the ratio of the current balance to your original balance.  To improve your score (slightly) you would want a lower ratio.  I would recommend paying your student loan down to 75% ratio as fast as you can and then you can go back to $50/month. A much better way to improve your FICO score is to have revolving credit.  Your student loans are not revolving, they are installment loans.  Therefore, you should open at least one credit card (assuming you currently have none) right away.  The longer you have had a credit card open, the better your FICO score gets.  Your revolving credit utilization ratio is way more important than your installment loan ratio.  Therefore, to maximize your FICO, try to never have more than 10% utilization on your revolving credit report to the credit bureaus each month.  Only the current month's ratio affects your score at any given moment.  You can ensure you don't go above 10% by paying your balance before the statement cuts each month to get it below 10% way before any payment would be due.  (You should always pay your remaining credit card statement balance in full each month by the due date after the statement cuts to avoid any interest charges.)  Note that there is a slight FICO advantage to having at least one major bank credit card instead of just only credit union credit cards.  Also, never let all your revolving credit report a zero balance in a month, you must always have at least $1 reporting to the credit bureaus on at least one of your open credit cards or your FICO score will take a big negative hit. If you cannot get a normal credit card, go to a credit union and find one that offers secured credit cards, or a bank that does.  A secured credit card is where you place a deposit with the bank that they hold and give you a credit limit to match your security.  Ideally it would be a card that graduates to unsecured after your demonstrate good history with them.  For example, the Navy Federal Credit Union secured card unsecures for many people.  I also believe the Wells Fargo Bank credit card (you can join if there is a family member who served or a roomate who did) also will unsecure.  The reason you want it to unsecure and not be forced to open a new account to get an unsecured account is that you want your average age and oldest age of open revolving credit accounts to be as high as possible as this is another impact on your FICO score. Credit unions that anyone can join include, Digital Federal Credit Union, the Pentagon Federal Credit Union (which offers a secured card that does not graduate), and The State Department Federal Credit Union (also offers secured card that I think does not graduate). One other method to boost your FICO score is to get added as an authorized user on one of your parent's credit cards that has been open a long time.  Not all lenders will report such an authorized user, however, ones that are known to do so are: Bank of America, Citi Bank, and Capital One.  It is a good sign that it will report if they ask for the social security number of the authorized user. However, note that the Authorized User addition can have no impact if the lender is using one of the newer versions of the FICO scoring model, only the older versions reward you for the age of accounts for which you are an authorized user. A very long term boost is to open your first American Express card underwritten directly by Amex such as their Zync card which is pretty easy to get.  The advantage of American express is that they remember the date your first credit card was opened with them and if you open new accounts in the future they will back date the date of their opening to match the date your first card was opened.  If you let your membership lapse, be sure to record the account number and date opened in your personal files so that you can help them locate it again if you reopen as they can have trouble if it has been on the order of ten years or more. Finally, note that the number of accounts opened in the last twelve months is a small negative mark on your score (along with number of inquiries), so if you open a lot of accounts all at once, in addition to bringing down your average age of accounts, you will also get dinged for how many were opened in the last year. Unfortunately not. Even if the credit card balance is positive (i.e. customer has overpaid the credit card account), you cannot withdraw cash (for free) - as any cash withdrawal is subject to 12.9% interest - even if repaid in full at the end of the month! The clarity credit card is one of the best cards for overseas spending, as its load free (no fees for purchases abroad) and it gives near perfect exchange rates. If your balance is positive, you start at £0, then fund that credit card account from your bank account £500. You can then spend on your credit card, and when your next bill is due at the end of the month - they will use that extra £500 sitting in your account first, and ask for the remainder from you. i.e.  scenario1:  scenario 2: It is better in my opinion, to set up a direct debit to always clear out the full amount on your credit card. That way, you have cash in your bank account for emergencies (getting £500 back from a credit card will take a few days to process as opposed to having the ability to withdraw cash from the cashpoint 24/7). And once the direct debit is paid automatically at the end of the month, there are no fees - voila your credit card is almost like a debit card, spend on it when you like, it gets paid automatically, no hassle, no worries. This approach does take a careful mindset though, as you need to know your credit limits and also you need to ensure your bank account has enough to pay off the direct debit at the end of the month. Otherwise those darn fees will get you (and hurt your credit rating). For cash spending, you will want to either take cash with you (check online here for best rates & get the money well in advance to avoid fees). Also in some countries the exchange rate is better there, than in the UK, google will help you here. If you dont like the idea of carrying large sums of cash with you can use a prepaid card like CaxtonFX, which is one of the better ones out there. The other well known ones are FairFX and Travelex Cash Passport. "To expand on @JoeTaxpayer's answer, the devil is actually in the fine print. All  the ""credit-card checks"" that I have ever received in the mail explicitly says that the checks cannot be used to pay off  (or pay down) the balance on any other credit card issued by the same bank, whether the card is branded with the bank logo or is branded with a department-store or airline logo etc. The checks can be used to pay utilities, or even taxes, without paying the ""service fee"" that is charged for using a credit card for such payments. The payee is paid the face amount of the check, in contrast to charges on a credit card from a merchant who gets to collect only about 95%-98% of the amount on the  ""charge slip"". Generally speaking, balance transfer offers are a bad deal regardless   of whether you pay only the minimum amount due each month or whether   you pay each month's statement balance in full by the due date or   anything in between. The rest of this answer is an explanation in support of the above assertion. Feel free to TL;DR it if you like. If you make only the minimum payment due each month and some parts of the balance that you are carrying has different interest rates applicable than other parts, then your payment can be applied to any part of the balance at the bank's discretion. It need hardly be said that the bank invariably chooses to apply it to pay off the lowest-rate portion. By law (CARD Act of 2009), anything above the minimum payment due must be applied to pay off the highest-rate part (and then the next highest rate part, etc), but minimum payment or less is at the bank's discretion. As an illustration, suppose that you are not using your credit cards any more and are conscientiously paying down the balances due by making the minimum payment due each month. Suppose also that you have a balance of $1000 carrying 12% APR on Card A, and pay off the entire balance of $500 on Card B, transferring the amount at 0% APR to Card A for which you are billed a 2% fee. Your next minimum payment  will be likely be $35; computed as $10 (interest on $1000) + $10 transfer fee + $15 (1% of balance of $1500). If you make only the minimum payment due, that payment will go towards paying off the $500, and so for next month, your balance will be $1500 of which $1035 will be charged 1% interest, and $465 will be charged 0% interest.  In the months  that follow, the balance on which you owe 1% interest per month will grow and the 0% balance will shrink.  You have to pay more than the minimum amount due to reduce the amount that you owe. In this example, in the absence of the balance transfer, the minimum payment would have been $20 = $10 (interest on $1000 at 1% per month) + $10 (1% of balance) and would have left you with $990 due for next month.  To be at the same point with the balance transfer offer, you would need to pay $30 more than the minimum payment of $35 due. This extra $30 will pay off the interest and transfer fee ($20) and the rest will be applied to the $1000 balance to reduce it to $990. There would be no balance transfer fee in future months and so the extra that you need to pay will be a little bit smaller etc. If you avoid paying interest charges on credit cards by never taking any cash advances and by paying off the monthly balance  (consisting only of purchases made within the past month) in full by the due date, then the only way to avoid paying interest on the purchases made during the month of the balance transfer offer is to pay off that month's statement in full (including the balance just transferred over and the balance transfer fee) by the due date.  So, depending on when in the billing cycle the transfer occurs, you are getting a loan of the balance transfer amount for 25 to 55 days and being charged 2% or 3% for the privilege. If you are getting offers of 2% balance transfer fees instead of 3%, you are probably among those who pay their balances in full each month, and the bank is trying to tempt you into doing a balance transfer by offering a lower fee. (It is unlikely that they will make a no-transfer-fee offer.) They would prefer laughing all the way to themselves by collecting a 2% transfer fee from you (and possibly interest too if you fail to read the fine print) than having you decline such offers at 3% as being too expensive. Can you make a balance transfer offer work in your favor? Sure.  Don't make any purchases on the card in the month of the balance transfer or during the entire time that the 0% APR is being offered. In the month of the transfer, pay the minimum balance due plus the balance transfer fee. In succeeding months, pay the minimum balance due (typically 1% of the balance owed) each month. All of it will go to reducing the 0% APR balance because that is the only amount owing. Just before the 0% APR expires (anywhere from 6 to 24 months), pay off the remaining balance in full.  But remember that you are losing the use of this card for this whole period of time. Put it away in a locked trunk in the attic because using the card to make a purchase will mean paying interest on charges from the day they post, something that might be totally alien to you." "Many people who do transfer a balance from one credit card to another have no clue as to what is going on and how credit cards work. If you transfer a balance from one credit card to another, you are charged a fee of anywhere from 3% upwards (subject to a minimum of $10 or so) up front. If Credit Card A has balance $1000 and you transfer it to Credit Card B which is offering no interest for a year on the transferred balance, you owe Credit Card B $1050 (say). In most cases, that $50 has to be paid off as part of the following month's bill. If you are carrying a revolving balance on Credit Card B, that $50 will typically be charged interest from the day of the transfer. Your monthly bill will not (necessarily) include that $1000  you owe for one year or six months or whatever the transfer agreement you accepted says. If you tend to pay anything less (even a penny) than  full payment of each month's bill on Credit Card B, your partial payment will be applied to that $1000 first, and anything left over will be applied to the monthly balance. In short, if you don't pay in full each month, that $1000 will not be ""yours"" for a year; you may end up paying $50 interest for  borrowing $1000 for just one or two months, and the rest of your balance is the gift that keeps on giving as the credit card company likes to say. UPDATE: This has changed slightly in the United States. Any amount paid over the minimum amount due is charged to the higher-interest balances. So in this case, if you had $1000 at a 0% promotional rate and a regular balance of $500, and the minimum payment was $100, and you paid $150, $100 would pay down the promotional balance, and the extra $50 would pay down the regular balance.  About the only way to make the deal work in your favor is to Transfer money only if you have paid the full amount due   on the last two statements before the date of the transfer and are   not carrying a revolving balance. Check your monthly statements   to make sure they show Finance Charge of 0.00.  Many people have   never seen such a sight and are unaware that this can be observed   in nature. Make sure that you pay each month's bill in full (not   the minimum monthly payment due) each month for a whole year   after that. Make sure that the bill containing that $1000 (coming out a   year after the transfer date) is also paid in full. Very many credit-card users do not have the financial discipline to go through with this program.  That is why credit card companies love to push transfer balances on consumers: the whole thing is a cash cow for them where they in effect get to charge usurious rates of interest without running afoul of the law. $50 interest for a one-year loan of $1000 is pretty high at current rates; $50 interest for a two or three month loan where the customer does not even notice the screwing he is getting is called laughing all the way to the bank. See also the answers to  this question" The difference in interest is not a huge factor in your decision.  It's about $2 per month.   Personally I would go ahead and knock one out since it's one less to worry about.  Then I would cancel the account and cut that card up so you are not tempted to use it again. To address the comments... Cutting up the card is NOT the ultimate solution.  The solution is to stop borrowing money... Get on a strict budget, live on less than what you bring home, and throw everything you can at this high-interest debt.   The destroying of the card is partly symbolic - it's a gesture to indicate that you're not going to use credit cards at all, or at least until they can be used responsibly, not paying a DIME of interest.  It's analogous to a recovering alcoholic pouring out bottles of booze.  Sure you can easily get more, but it's a commitment to changing your attitude and behavior. Yes leaving the card open will reduce utilization and improve (or not hurt) credit score - but if the goal is to stop borrowing money and pay off the other card, then once that is achieved, your credit score will be significantly improved, and the cancelling of the first card will not matter.  The card (really both cards) should never, ever be used again. "Yes and No.  There's always a ""fee"".  The difference in credit vs debit usually determines how much that fee is and how it's paid.  Each vendor who accepts the major credit card is under contract to pay for equipment and meet certain standards.  The same is true for debt card transactions.  How much the ""fee"" is can vary based on the contract the vendor has with MasterCard/Visa/AMEX.  But in general most debt transactions go back to the bank who distributed the card."