Pay bill now or later?
If you've got the money to pay the bill today, do it. They are giving you a 25% discount if you do. You won't find an investment that will beat that.  Let's look at the details of your scheme.  Instead of paying $1696 today, you decide that you will pay $2261 over 60 months, or $37.68 per month.  You also decide to invest $1696 today, and expect to get 6% return each year. Your investment gets you $102 each year, but you have to pay taxes on that.  If you are in the 25% tax bracket, you only keep $76 (ignoring state taxes).  In addition, the loan is costing you $452 in payments each year. At the end of the 5 years, you will have paid $2261 to the hospital, and your $1696 investment will be worth about $2123 after taxes. Instead, let's say that you paid the hospital $1696 today, and invested the $37.68 per month.  At the end of 5 years, assuming the same 6% growth and 25% tax bracket, your investment will be worth $2552. In order for you to come out ahead by investing today and paying off the hospital over time, you would need to get at least a 17% growth on your investment.  If you are ignoring taxes, then the number you need to hit is at least 13%. Conclusion: You will come out ahead by paying the hospital today, and investing the monthly payment plan that you avoided. (Note: Bankrate has a very handy investment calculator that makes it easy to calculate returns on a monthly investment.) Now, let's look at the ethics of the situation.  Assume that you were able somehow to find an investment with a guaranteed return high enough to come out ahead with your plan.  Should you do it? The hospital has provided you a service, and you owe the money.  As a public service to people that cannot pay the bill, they allow people to pay off the bill over time at no interest.  However, you are not one of these people.  You have the money to pay.  It is not ethical, in my opinion, to use the hospital's money to invest and try to profit. Another, perhaps simpler approach to the same result as @BenMiller. Firstly, if you can pay off the debt today, for 1695.70 cash, then that is the amount of your debt to the hospital.  There is no such thing as a discount for cash; just extra money to pay if don't pay immediately.  This extra money is called interest, and the hospital is indeed charging you interest. Use any mortgage program to find the interest rate if you pay off a debt of 1695.70 with 60 monthly payments of 37.68.  The program should tell you that you are paying 12.64% effective annual interest. If you can earn more than that, after taxes, with your money somewhere else, then invest the cash there and pay off the hospital over time.  If you can't, then pay off the debt immediately, and avoid writing 60 cheques. EDIT:  Incorrect calculation revised as per @Ben Miller
There is a reason - your credit score. If you ever take out a mortgage, you might pay dearly for your behavior. The bank where you have the credit card reports the amount on the bill to the credit rating agencies. If you pay before the bill date, they will always report zero. You should wait at least till the day after the billing cycle ends, and then pay off (you don't need to have the paper bill in your hands - you can see online when the cycle closed). Depending on your other financial behavior, this will have between zero and significant effect, on the percentages you get offered for car loans, mortgages, etc. I don't believe Saturday is a business day either. When I deposit a check at a bank's drive-in after 4pm Friday, the receipt tells me it will credit as if I deposited on Monday.  If a business' computer doesn't adjust their billing to have a weekday due date, they are supposed to accept the payment on the next business day, else, as you discovered, a Sunday due date is really the prior Friday. In which case they may be running afoul of the rules that require X number of days from the time they mail a bill to the time it's due.  The flip side to all of this, is to pick and choose your battles in life. Just pay the bill 2 days early. The interest on a few hundred dollars is a few cents per week. You save that by not using a stamp, just charge it on their site on the Friday. Keep in mind, you can be right, but their computer still dings you. So you call and spend your valuable time when ever the due date is over a weekend, getting an agent to reverse the late fee. The cost of 'right' is wasting ten minutes, which is worth far more than just avoiding the issue altogether.  But - if you are in the US (you didn't give your country), we have regulations for everything. HR 627, aka The CARD act of 2009, offers - ‘‘(2) WEEKEND OR HOLIDAY DUE DATES.—If the payment due date for a   credit card account under an open end consumer credit plan is a day on   which the creditor does not receive or accept payments by mail   (including weekends and holidays), the creditor may not treat a   payment received on the next business day as late for any purpose.’’. So, if you really want to pursue this, you have the power of our illustrious congress on your side. If you have the ability to pay online with a guaranteed date for the transaction, go for it. My bank will let me pay a bill on the exact date i choose. When using the mail, of course, this introduces a level of risk.  I asked about rates as the US currently has a near zero short term rate. At 3.6%, $10,000, this is $30/month or $1/day you save by delaying. Not huge, but better in your pocket than the bank's. I'm really going to go against the crowd here--paying it too fast could be a problem. The thing is you want them reporting that you paid the bill as agreed.  To do that you need to pay the bills--which means you need to leave the charges there to get billed for.  Paying less than the total is fine, paying as soon as they bill you but before you even get the bill is fine. "In the US, you'd run the risk of being accused of fraud if this weren't set up properly.  It would only be proper if your wife could show that she were involved, acting as your agent, bookkeeper, etc. Even so, to suggest that your time is billed at one rate but you are only paid a tiny fraction of that is still a high risk alert.  I believe the expression ""if it quacks like a duck..."" is pretty universal. If not, I'll edit in a clarification.  note -I know OP is in UK, but I imagine tax collection is pretty similar in this regard." CTRs are made all the time, and yes, the banks do need to consider one-off transactions that aren't $10,000 per se but amount effectively to $10,000 or more. But if you're doing nothing improper, just pay your bill and be done with it.  No need to split it up just for this reason. They don't do anything you can't do yourself and they charge you money for it. And of course the only way they manage to negotiate the debt down is by not paying it for a while in the first place, have it referred to collections and then negotiating with the collectors. At that time, your credit rating (if you care about that at all) will have suffered a lot more damaged than it is from a few late payments. I would address the issue as to why you end up paying late first - it sounds to me like you're cutting the time left to pay to the bone and this turned around and bit you in the you-know-where. In case you are able to pay but not organised enough to do it on time, find a way to remind yourself to pay the bill a few days early for peace of mind. That won't do anything about the 28% interest but those might serve as an additional motivation to pay the debt off faster. Once you're back to showing regular on-time payments on your credit record, you might want to investigate transferring the balance to a cheaper card or negotiate the interest down (or both). If you genuinely can't pay after you've taken care of the essentials (food, shelter, transportation) then you don't need a third party to stop paying the credit card bill, you can do that yourself. "Is there any practical reason... to hold off on making payments until I receive a billing statement? Yes, a few:   As for a zero balance, FICO consumer affairs manager Barry Paperno says, ""The idea here is the lower, the better, in terms of the utilization percentage, but something is better than nothing....The score wants to see some kind of activity.""  How low should you go? In a recent interview, FICO spokesman Craig Watts said, ""If your utilization is 10 percent or lower, you're in great shape as far as utilization goes."" That being said, there are downsides especially if you wind up forgetting to make a payment.  The easiest thing to do (also from a time management perspective) is to get your billing statement once a month, verify the purchases on it, and at that time you receive the statement schedule an online bill payment so that it will be paid in full before the due date.   As Aganju points out, you don't have to wait for a paper bill in hand or even an e-mail notification; you can go online after your statement date to get the statement.  This makes sure you won't have extra costs related to unreliability of mail (if you still receive paper statements)/e-mail, though it does require remembering to check (and/or setting a recurring calendar reminder).  Paying much in advance of that, as is your current practice, might be a good idea to free up available balance if you are planning a purchase that would take you over your credit limit, but this should be relatively rare (and some credit card companies will raise that limit if you have been paying well and ask nicely, though find out first if they do a ""hard pull"" of your credit report for that)." I am sorry for your troubles.  Presumably, you are feeling better which is the best possible outcome.  You project that you are an honest person and desire to seek a fair outcome although you were mistreated.  The insurance company should have paid a good portion of this bill. Because of this situation you will learn a valuable lesson.  Namely that collectors are scum.  They lie and manipulate to do their job.  They are trying to generate an emotional reaction out of you so you give in an put this bill on a credit card.  Do not fear them. My advice would be to ignore them.  You can educate yourself on collections law in your state.  They cannot call you at work and they probably cannot call you on a cell phone.  They will threaten to garnish your wages, tax return, and take away your birthday.  Just don't talk to them. When you can save up some money.  Once you have like $1200 attempt to settle in full for that amount.  Get it in writing ahead of time and do not give them access to your checking account.  Use a cashiers check or prepaid visa (that you then throw away).  If they say no, do not argue, hang up and call back when you have 1300.  Rinse, wash, repeat.   There is a decent chance that they have already violated some form of collections law.  If you have proof you can call the company's legal department and provide that proof.  You can then settle on having your collections waived.  In summary: This also presumes you have a lowish household income.  If you make like 70K, jut pay the bill.  I doubt that is the case though. In month 9 you still owe $7,954.25. You need to pay that, plus the $250. At that line, you haven't made the payment, the rest of the line with next month's payment due. So you haven't paid the $242.47 in col 4. When in doubt, call (the card issuer) and ask. Ask if you overpay your current bill if the overpayment becomes available credit and tell them why you are asking. It can go either way. Ally bank has a free billpay service where you have the option of paying bills via eBills. Though I use Ally's billPay service (and I write about my experience with Ally in my blog), I haven't used eBills, but from reading your question, looks like this is what you are looking for. From Ally's site: What are eBills? An eBill is an online version of a bill or statement that can replace a traditional paper copy. Many large companies, like your electric, phone, cable and major credit card companies have the ability to send you eBills. To receive eBills at Ally, you must already receive your bill online at the biller's website. Ally will ask for the biller's website credentials to set up an eBill. Hope this helps. If the bank wants to close your account, they will do just that. Having a small ongoing balance isn't going to prompt them to keep it open.  Typically, the risk is for a card with zero usage to be closed, as it's a cost to them to keep the account open, and it has no revenue. To avoid this, it's a good idea to use that card or cards for a regular purchase, say, gasoline. A non-impulse buy, and just pay in full to avoid interest. There's no need to keep a balance accruing interest.  Keep in mind - A bill contains a month of charges. The bill for December is issued on the 31st, but due January 25th or so. When you pay it in full you do not have zero balance, you have the charges from January. This accomplishes your goal, will no interest. You're knowingly providing a payment method which has insufficient funds to meet the terms of the contract, because you are too lazy to comply with the contract. That's unethical and fraudulent behavior. Will you get in trouble? I don't know. I'd suggest getting acquainted with an electronic calendar that can remind you to do things. If they had told me that I owe them $10,000 from 3 years ago, I   wouldn't have anything to fight back. Why? First thing you have to do is ask for a proof. Have you received treatment? Have you signed the bill when you were done? This should include all the information about what you got and how much you agreed to pay. Do they have that to show to you, with your signature on it? If they don't - you owe nothing. If they do - you can match your bank/credit card/insurance records (those are kept for 7 years at least) and see what has been paid already. Can a doctor's office do that? They can do whatever they want. The right question is whether a doctor's office is allowed to do that. Check your local laws, States regulate the medical profession. Is there a statute of limitation (I'm just guessing) that forces them   to notify me in a certain time frame? Statute of limitations limits their ability to sue you successfully. They can always sue you, but if the statute of limitations has passed, the court will throw the suite away (provided you bring this defense up on time of course). Without a judgement they cannot force you to pay them, they can only ask. Nicely, as the law quoted by MrChrister mandates. They can trash your credit report and send the bill to collections though, but if the statute of limitations has passed I doubt they'd do that. Especially if its their fault. I'm not a lawyer, and you should consult with a lawyer licensed in your jurisdiction for definitive answers and legal advice.