If you consider your credit card to be a no-fee (or low-fee) payment mechanism that aggregates your monthly expenditures into a single bill, you can have savings theoretically (though in reality, probably not usefully) appreciating over the course of the month in a bank account, and then pay the bill for your expenditures at the end.

This simple money management technique reduces fees paid for ATM access, allows your assets to maximally appreciate, and builds up a very solid credit history. Credit Cards and Lines of Credit aren't evil; they're useful, but they're not hard to use in a manner that will bite you.

* Pay the entire balance every month, ideally by direct debit (they don't like doing this) * Ignore offers to increase credit limit * Actively reverse automatic credit increases. My card company tried ridiculously hard to talk me out of reducing my credit limit.

This type of credit card customer is by far the minority (10% iirc), and least welcome to the card companies. Their ideal customer has multiple cards and pays minimum balance every month.

Student loans also count towards credit worthiness.

For a home loan, having little or no credit, isn't necessarily a deal breaker, but does limit lender choice. At least in the UK.

I dislike the game partially because the more indirection between spending and the actual money, the easier it is to overspend or lose track. This is the whole point, of course! So I just stick to the debit card for net, and actual cash from ATM when out shopping.

I do know the UK doesn't use credit score as the US does, so it may operate on a different premise where gaming the score matters.

A card user who pays their balance every month is still valuable to the card company though, as it draws fees on every transaction. Someone who uses their 1.5% cashback card to pay for EVERYTHING and puts a couple thousand a month on the card brings in some cash too, and the day they lose their job they might start racking up debt.

At one point I had as much available credit across two cards as balance on the mortgage, whereupon I decided it was silly and I'd like them to reduce please.

Why? They are giving you free money for your trouble (1.5-2% back, a proportion of the transaction fee they've effectively baked into the price of all consumer products) and offloading the risk of having your bank account drained through a debit card or getting mugged for your cash.

Time was you got tax relief on mortgage interest, and crucially there was enough inflation in the system that a mortgage was an insanely easy choice. A little inflation would deflate your mortgage payment down to truly trivial levels over the life of the mortgage. Because of the removal of inflation your mortgage payment is no longer an ever decreasing proportion of your income, ignoring pay rises, so the only remaining factor is what you believe will happen to rents.

Our credit score were upper good before and near perfect now. We've not used a credit card in eight years.

You can get a free copy of your credit report once a year from each major company - you could go ahead and order them just to see where you are at.

There are many reasons to use one. Others here have already given you some. But I want to add one more good reason: protection. So here you go:

- I try to pay for all restaurant meals with a credit card. Then, e.g. if I get sick eating at e.g. Chipotle, there's at least a record that I purchased something from them. If I lose the receipt I might not remember whether it was a taco or a burrito, but I'm still way ahead of someone who paid cash and doesn't have his receipt!

- If I have a dispute of any sort with the supplier, it really helps to at least have the threat of a credit card chargeback available. Too many disputes or chargebacks are bad news for vendors, and most will want to avoid those.

- Some cards will extend the warranty on a purchase, but I've never availed myself of that feature so I don't know how easy it is to use.

I've also used price protection with Discover. Also easy to use but they take a couple weeks to process the claim and mail the check (a third party processes it)

Price protection is pretty unique - not too many cards have it. If you find a lower price later on an identical item they refund the difference. I used it to get black friday sales before black friday.

Debit card?

The lender wanted to see loan with fixed payments in the past 3 years (which my wife had, a car loan). Sure, maybe we could have argued, etc. but a credit card paid off each month wasn't a magic bullet for building credit history. I'd say get a nominal loan (not simply a credit card) to build up credit.

"Not paying interest on any card" is desirable. "Not having any card" works against you in your situation.