The no.1 personal finance advice is pay your credit card balance in full every month.

The exception is when you have a credit card offering a 0% interest promotional period. As long as your overall credit utilization is low, you can pay the minimum each month to maximize the amount of time your money sits collecting interest. I usually pick up a new 0% promo card every year to get cheap financing for large purchases while my money appreciates in the stock market.

The amount of interest a savings account is going to accrue in that time is negligible to the point of being worthless.

Nope. Invest the money into an S&P 500 ETF and you’ll probably gain 10% profit by the time you have put down your last payment.

The S&P return is not always and certainly not guaranteed to be 10% or even positve. Some months/years it is negative. It's an exceedingly bad idea to keep cash that you will need in the short term (< 5 years) invested in equities.

If you sell OTM covered calls of about 10 or 8 delta against the shares you own and keep rolling them after sufficient theta decay you can conservatively add 1% ROI each month on top of whatever appreciation your shares get. So yea you have a good chance of getting 10% ROI per year consistently this way unless S&P is down more than 2% for the year.

Unfortunately so many people use this strategy these days that the bids are lower than what they used to be though.

In the UK, at least, if a transaction paid with a credit card is between £100 - £30k and the merchant becomes unable / unwilling to render the goods / services, you get the full amount back under Section 75 of the Consumer Credit Act. This is to prevent people from being in debt for things they never receive. You don't get that protection with a debit card.

I'm sure other countries have similar protection.

AFAIK in the US, the merchant is not allowed to charge the card until the good/service has been delivered (or shipped). I'm sure some do anyway...

> you're using the money you have vs. taking a loan?

Why would you want to use the money you have when you can take a free loan until the end of the month? A free loan means you can keep your own money invested or otherwise working more efficiently for you somehow.

> the no.1 personal finance advice is "stop using CCs"

I've never seen this - I see 'use CC's more to build up your credit'. I use my cards religiously and have near perfect credit based on I think basically on this alone as it's the only credit I use beside my mortgage.

The problem is that most people lack discipline and run up debt. Using CCs is fine if you are extremely disciplined.

Dave Ramsey made a career out of teaching “normal” undisciplined people how to avoid and eliminate debt and that includes the advice of “never ever use credit cards or get loans.” A 15 year home mortgage with 20% or more down is the only acceptable debt in his eyes. (And that’s because human nature often leads people into debt, not because of any mathematical basis.) For the majority of “normal” people, he’s right.

We don't spend nearly enough time in primary and high school teaching practical personal finance. For many people that could be the single most important life skill they learn in 12 years of education.

You keep trying to make this "keep your money invested for a month" argument but without actual numbers I don't believe it. How much are you spending in a month that you actually get any kind of investment return on it? And what is your return?

> Why would you want to use the money you have when you can take a free loan until the end of the month?

Because it's usually not free. Most banks charge some fee for providing a credit card. Debit cards are completely free with most banks.

You should really shop around! In Europe I have a free credit card, with a large line of credit, that I literally never pay any interest on, that (used to) fly me to New York in first class once a year on normal household and business expense spending. They're out there - you're throwing away money by not using them.

In the US it's easy to get a zero-fee credit card. Most have rewards programs.

The personal finance advice I've heard is not "don't use credit cards" it is "don't carry a balance on credit cards."

Carrying a balance will eat you alive on interest. As will fees for late payments or going over the limit. If you have the self-discipline to not do those things, there's no reason to not use a credit card.

The thing is CCs basically give a zero interest rate loan for upto 45 days. This means if you spent 1000£ through CC rather than a debit card, the 1000£ will sit in your bank account and earn interest, also 1000£ spent on the CC would have earned you reward points that could be redeemed as a statement credit. Thus in effect by using CC, one would have spend less for the same transaction.

Also taking credit and closing them in time with CC could boost one's credit score, which may be useful in the future ocassion when one requires a bank loan.

Is that not sane personal finance advice?

> the 1000£ will sit in your bank account and earn interest

You typically use a non-savings account to back a credit card. 0% interest

Most savings accounts give in the area of 0.01% interest.

While you’re right in general that you’d wanna use credit and keep cash for many things, a typical CC transaction is too small for this to be worth considering.

Use a CC for the points and pay it off every month. Forget the interest gains.

Make sure you don’t not pay. The interest on a CC loan will kill you. And that’s far more common for most people.

I don't know your country, but in many countries banks allow savings account with reasonable interest rates to back a CC. Sometimes they provide automatic gathering up of parked funds in the savings account into a higher interest rate deposit account of even higher interest rate.