Year ended
31 March
2005
£m
  2005
£m
2004
£m
509 Rent receivable 293 241
40 Spreading of tenant incentives/guaranteed increases 27 11
8 Surrender premiums 7 5
47 Service charge income 13 21
604 Gross rental and related income 340 278
(44) Service charge expense (9) (19)
(43) Property operating expenses (26) (22)
517 Net rent and related income 305 237

In anticipation of quarterly reporting from 31 December 2005, the basis of recognising rent receivable in the period has been adjusted to ensure that rent is spread evenly over the year. Previously, a method based on the actual number of days in each billing period led to higher second half profits compared to the first half, due to the varying lengths of English rent quarters. The effect in the current period is £6 million. As described in note 1, increases arising on rent review are recognised from the rent review date. This has led to additional rent of £2 million being accrued in the period, but prior periods have not been restated as the effect is not considered material.

Net rental income for the half year to 30 September 2005 from properties which were subject to a security interest or held by non recourse companies was £198 million (year ended 31 March 2005: £374 million).