0001487428 2023-06-28 2023-06-28 0001487428 hrzn:CommonStockParValue0001PerShareCustomMember 2023-06-28 2023-06-28 0001487428 hrzn:NotesDue20264875CustomMember 2023-06-28 2023-06-28 0001487428 hrzn:NotesDue2027625CustomMember 2023-06-28 2023-06-28 false 0001487428 8-K 2023-06-28 HORIZON TECHNOLOGY FINANCE CORPORATION DE 814-00802 27-2114934 312 Farmington Avenue Farmington CT 06032 860 676-8654 false false false false false Common Stock, par value $0.001 per share HRZN NASDAQ 4.875% Notes due 2026 HTFB NYSE 6.25% Notes due 2027 HTFC NYSE