Hi N S,
Thank you for your question.
I can confirm that if you elect to claim the £1000 Property Allowance (and your rental income is more than £1000) then you cannot also claim any deduction for your rental property expenses.
You can either claim the £1000 allowance or the actual expenses incurred.
Please refer to the following guidance (under the section headed 'Allowances') for further information :
Work out your rental income when you let property
This refers to all types of expenses incurred including property repairs and maintenance and such things as building insurance,ground rent,property inspections and travel expenses.
If you elected to claim the actual property expenses you could enter the payments to a locksmith under Property repairs and maintainance or in the 'Other Allowable expenses' box on the return.
You will need to retain receipts for any expenses incurred in case they are requested by HMRC in the future.
Thank you