Landlord insurance requirements come from five different places and get muddled into one list, which is why landlords over comply in some directions and under comply in others. Sorting them by who is demanding what makes the obligations clear and makes it obvious which ones carry consequences.
Statute
Employers liability if you employ anybody, to a minimum limit, with a daily penalty for trading without it. That is the whole statutory insurance list. Statute demands a great deal else of landlords, gas, electrical and fire safety, deposit protection, right to rent, but none of it is an insurance requirement.
The mortgage
Buildings insurance for full reinstatement, against listed perils, continuously, with the lender's interest noted. Some lenders specify minimum terms or require notification of a change of tenant type. The consequence of breaching this is that the lender may insure the property itself and charge you, at a price you would not have chosen.
The lease and the freeholder
On a leasehold flat, the freeholder insures the structure and you contribute. Your lease may also require you to hold your own liability cover, and increasingly to notify the freeholder before letting. Reading the lease before letting a flat prevents most of the disputes that arise afterwards.
The letting agent and the local authority
Agents commonly require landlords to hold property owners liability at a stated minimum before they will manage a property. Local authorities may require evidence of specific cover as part of a selective or additional licensing scheme. Neither is statute, both are conditions of doing what you want to do, and both are easy to satisfy if known in advance.
Questions people ask about landlord insurance requirements
What insurance must a UK landlord have by law?
Only employers liability, and only if you employ anybody. Everything else comes from a mortgage, a lease, an agent or a licensing scheme.
What does a buy to let lender require?
Buildings cover for full reinstatement against listed perils, maintained continuously, with the lender's interest noted.
Can a letting agent insist on liability cover?
Yes, as a condition of managing the property, and many do at a stated minimum limit.
Does a licensing scheme require insurance?
Some do as a condition. Check the scheme's conditions before applying, because evidence is usually needed at application.