landlord1234 wrote:As a landlord , tax is payable on the 'rent after expenses, but no NI is payable , correct ?
Correct, although clearly employer's NI may be due if the landlord has employees.
landlord1234 wrote:If a landlord then employs someone , is he not then classed as self employed and liable for NI on the profit as well ?
Who's "he", the landlord or the employee? In any event, neither would be self-employed merely as a result of the landlord employing someone.
landlord1234 wrote:or is the salaries paid just another expense like those paid to agents and for repairs ?
Correct.
landlord1234 wrote:If a landlord did some self employed work would he/she onl;y pay NI on that income or on all his/her income including the rental income ?
Rental profits are not earned and therefore not subject to NI.