Halifax data shows UK average house price fell 0.5% in March to £299,677, ending February's 0.3% rise.
Annual price growth slowed to 0.8% from 1.2% as regional gains varied, with NI up 8.7% and London down 1.2%.
Halifax's Amanda Bryden cites Middle East conflict, higher energy prices and rising mortgage rates as dampening confidence in rate cuts.
February home sales rose 5.6% to 102,410 transactions, and mortgage approvals increased 3.9% to 62,584, the highest since March 2025.