Can all service charges and building improvements be deducted from the rental income?

Can all Service Charges and Building Improvements carried out by a Leasehold Management Company be deducted as a cost from the rental income of a Buy-to-Let property?

Arthur Says

All service charges can be deducted. Building improvements can be deducted if they are revenue expenses, but not if they are capital expenses. It is not easy to distinguish between the two, but, in a nutshell, revenue expenses are small repairs, general upkeep, like painting, and 'like for like' replacements; whereas capital expenses are extensions, big repairs and replacements that are a major upgrade from the original.