The changes will apply to personal loan customers in January 2009.
Lloyds is predicting the transition to the monthly product will reduce the bank’s income by around £300m over the next twelve months.
The lender is also allowing for an additional £120m to cover the cost of the Financial Services Compensation Scheme to pay out any savers who lose money in failed banks.
Lloyds has written off a further £30m as part of the sub-underwriting it carried out for Bradford & Bingley’s rights issue earlier this year.
Lloyds has played down the impact of HBOS’ total write-downs of £8bn for the first eleven months of the year.
A statement from the bank says: “The trading update from HBOS is broadly consistent with the impairment analysis conducted by Lloyds TSB as part of its review process in October 2008.
“The fair value adjustments can only be finalised after the completion of the acquisition and in accordance with market conditions at that time.
“But the additional impairment losses being incurred by HBOS are not currently expected to have a significant impact upon the size of the net negative capital adjustments the group is likely to make upon acquisition.”