You can deduct the full amount, even if you did not issue a 1099.
Landlords are not require to issue 1099 forms to service providers.
Reference: http://www.forbes.com/sites/irswatch/2013/03/06/should-landlords-be-filing-1099s-for-service-provide...
But, a landlord 1099-NEC may be required to qualify for the QBI deduction. Reference: https://www.nolo.com/legal-encyclopedia/do-landlords-need-to-file-form-1099-misc.html Most rental properties do NOT qualify for the QBI deduction.
