You should receive a Dilapidations claim from your landlord near the end of your tenancy, giving you enough time to respond and either agree a settlement or carry out the required works before Lease End.
There is not however any requirement for a landlord to notify you of the works needed and you should be aware of your lease obligations and implement the works required. In some instances, a landlord will intentionally avoid notifying the works, as they prefer to claim for the cost of these after the lease has ended and you are no longer able to implement them.