Written for the demonstration, and labelled as such

I had never seen a lender site that started by asking how I get paid rather than which loan I wanted. Working out that my overtime would be averaged over two years rather than taken from last year's total changed the number I was shopping with, and I would much rather have learned that at the start than three weeks in.

Two years of a business that pays me well and a tax return that says otherwise. The bank-statement calculator was the first place anybody explained the expense factor to me — and that it is an assumption somebody chose, not a law. I went and asked my accountant for a letter.

I have been buying small multifamily for six years and nobody had ever pointed out that some lenders take vacancy off before working out the coverage ratio and some do not. That is the difference between two quotes I had been treating as the same.

Retired, comfortable, and repeatedly told I did not have enough income. The asset page finally explained the divisor — that the same savings can produce two completely different monthly figures depending on which number the programme divides by. I had assumed the answer was about the size of the account.

The line about the profit-and-loss statement and the bank statements having to tell the same story saved me a wasted fortnight. Mine did not. I got them reconciled before I applied anywhere.

First-time buyer, salaried, nothing complicated — and I still found the payment calculator useful because it was the first one that showed me the mortgage insurance separately and told me the month it would stop.

Seasonal income. Four good months and eight quiet ones. Being told plainly that twenty-four months of statements was close to essential for a file like mine, rather than being sold twelve because it is quicker, was worth the visit.

I liked that the site says out loud what it does not know. The rent-versus-buy page listing the tax treatment it deliberately leaves out told me more about how much to trust the answer than the answer did.

The DSCR calculator does the one thing most of them will not: it says the ratio tells you nothing about a void month or a new boiler. I ran my own numbers alongside it and bought a different building.

Freelance, nine clients, and two declines behind me for insufficient income history. Seeing the documentation route laid out as a route — with what goes in it and what trips it up — was the first time the process looked like something with a shape.

The amortisation schedule showing the month principal finally overtakes interest is the single most sobering thing I have seen on a lender's website, and I mean that as a compliment.

I came for the calculator and stayed for the page that lists what the site will not tell you. A lender that says it publishes no rates because a rate table goes stale the week it ships is a lender being straight with me.