Number of landlords underpaying tax jumps Analysis by the Telegraph shows that the number of landlords found to have underpaid or under-declared tax on income from letting their property rose by 51% during 2018 to 8,704. Figures from HMRC also reveal a 67% increase in the amount of income tax clawed back from landlords, which hit £32.8m in 2018, with the value of fines totalling £5.6m. Chris Norris, of the National Landlords Association, said: "Tax can be a complicated and confusing process for landlords who are trying to cut costs by doing their returns themselves, rather than seeking specialist advice. It is possible some landlords have unwittingly disclosed less tax on letting income than they should have." John Stewart, of the Residential Landlords Association, said: "The tax system is becoming ever more complex in the private rented sector, and communication from HMRC on changes to mortgage interest relief has not been sufficient."