Mortgage applications & credit record

Tirian

I intend to apply for a mortgage in the near future, so thought it might be a good idea to take a quick look at my credit record - expecting no problems.

Overall this was the case, however there is one blip. Among the 14 credit agreements showing on my Equifax report (which include several bank accounts and a number of credit cards), there is a marker for 2 late payments in January 2010 on a now closed Santander bank account.

In actual fact, what occurred here was that due to bank holidays over the Christmas period, my pay came in slightly after the beginning of the month - on the same day as some standing orders were due out. I was aware of this - but not of the fact that, unlike my other banks, Santander apply debits to the account before credits and therefore bounced two payments, charged me and then credited my pay.

I was extremely p**** off about this at the time, and rang to complain - they were not especially pleasant about it, but did agree to refund the charge - but I never imagined that they would mark this as a "late payment". I closed the account later that year, due to further incompetent behaviour.

My questions, in order of importance, are:

1) How likely is this marker to affect a mortgage application (success of, rates offered etc)?

2) Is it worth placing a note of correction on the report to describe what this was all about? Would this realistically make any difference?

3) Should I officially dispute the late payment markers? I've just had a look at their current account T&C on the web (I don't have actual ones they sent me at the time as I shredded all a year after closing the account). The current T&C do not, as far as I can see, make any mention of the order in which credits and debits are applied to the account.