Trends from the mortgage industry compiled by the lender (see below) show product transfers and remortgages were among the key drivers of activity over the period.
Product transfers outperformed remortgages both in the number of deals and in value.
Slightly more product transfer deals were advised at 156,000, compared to 135,000 carried out as execution-only.
The increased difference between typical two-year fixed rates and the average standard variable rate (SVR) could have helped drive the focus on switching.
The gap is now at 2.41%, as the average SVR stands at 4.85% compared to 2.44% for the average two-year fix.
And the relatively low rate of two-year deals show the muted impact of the Bank of England base rate in August.
Average property prices were at £225,995 in September, the Halifax house price index showed.