0001487428 2026-03-03 2026-03-03 0001487428 hrzn:CommonStockCustomMember 2026-03-03 2026-03-03 0001487428 hrzn:NotesDue2027625CustomMember 2026-03-03 2026-03-03 false 0001487428 8-K 2026-03-03 HORIZON TECHNOLOGY FINANCE CORPORATION DE 814-00802 27-2114934 312 Farmington Avenue Farmington CT 06032 860 676-8654 false false false false Common Stock HRZN NASDAQ 6.25% Notes due 2027 HTFC NYSE false