The Revenue is writing to about 100,000 mortgage holders advising them to return details of their annual mortgage interest payments if they want to continue to benefit from tax relief from January.

Because the system for applying mortgage interest relief is changing to tax relief at source on January 1st, 2002, there is danger that mortgage holders will not get the correct relief immediately if their lending institutions have not received instructions from the Revenue. The change was first announced in the budget speech on December 1st, 1999. Under the new system, lending institutions will deduct the tax relief at source from an individuals's monthly mortgage repayments.

At present, tax relief is applied through the tax system with the relief reducing mortgage holders taxable income and increasing take-home pay.