Which balance does Amex report for their Charge cards???

Finally somebody else who knows that 'balance' and 'previous balance' are not the same and that the 'balance' reported is the balance on the day the credit card issuer reports.
I actually do the same as you sometimes, not though to create a 0 balance but to avoid a double months worth of purchases being reported as the balance, which is what happens if I just leave the direct debit to go through.
On the subject of Amex chargecards, I'm very sorry but I don't know as I gave mine up some years ago but considering the short period between the statement date and the direct debit being taken, I would imagine that the previous months spend would be paid by the reporting date.
Just an observation, but how do you always manage to get a 0 balance? Either you must be paying before the statement date or not spending at all until after the reporting date. I don't really think you need to go that far; it does no harm for there to be some balance showing representing what you have spend during the current month.

molerat wrote: »

How does that work with CallCredit who report Status, Balance, Limit, Statement Balance and Payments ? I wonder if what is reported is different to what is shown by the different CRAs, some not showing all the figures. Equifax only report statement balance and limit in the history but report current balance and payments for the current month.

It would appear so. The credit report that I monitor regularly and to which I have unlimited access to the full report through my packaged bank account is Experian.
It shows for each statement period:
Status
Balance
Payment
Previous Balance
(Cash withdrawal info and 'markers' appear below)
The previous balance is the statement balance . The payment is the amount paid in respect of the statement issued for the amount of the previous balance. The balance, at the top, is the actual balance of the account on the reporting date and is 2 months out from the other 2 figures.
For example, if an entry read
balance 3421
payment amount 2100
previous balance 2100
and referred to the January statement, 2100 would be the statement balance and amount paid in respect of the statement issued 11th Jan the balance figure would be the balance at the reporting date in March, which appears to be a couple of days before the payment due date.
The illustrative figures in this example show the sort of balances being reported for a monthly credit card spend of approximately 2K representing almost 2 months spend. It is this balance figure, not the statement balance figures, which appears as my 'balance' and is used to calculate the utilisation ratio.
IF I am not happy to have this level of balance being reported, by paying a few days before the payment due date instead of leaving the direct debit to go through, I can substantially reduce the 'balance' reported simply by paying the already issued statement a bit early and forgoing a weeks interest on the money.

nic_c wrote: »

Is having a zero balance all the time for reporting good though? Surely could be seen as a negative for future CC applications as someone who spends and clears the balance so could be an unprofitable customer. Paying afterwards, e.g. letting the DD happen, could still mean no interest charged but a balance reported.

I think you have slightly misunderstood - see illustrative example above.
I don't quite agree with your reasoning in that a person who avails themselves of 5 days interest free credit is less profitable than someone who avails themselves of 56 days interest free credit.
I don't agree with the OP habitually repaying before the statement has been issued as I think doing so to have a 0 reported balance is unnecessary in that it looks very odd that somebody who uses a credit card regularly always has a 0 balance. Remember the 'ideal' utilisation ratio is apparently 10% not 0%..
As the stated purpose is for a mortgage application, and if the OP wishes a credit report with a 0 balance at the time of the mortgage application, it is only necessary to do this once in the period prior to the actual mortgage application and not use the card again. The payment history shown in the credit report will clearly indicate that the card has always been repaid in full; the mortgage lender will be interested only in current, not historical, balances.