Does your bank offer the midata download? That's a .CSV of the last 12 months' transactions, intended to facilitate account comparison by uploading the resultant file to comparison websites (e.g. gocompare.com), but obviously available for other purposes.
When it was launched in March, Barclays, HSBC (including First Direct), Lloyds, RBS (including NatWest) and Santander offered it. Possibly others have followed suit.