0001487428 2025-01-01 2025-12-31 0001487428 2026-04-29 0001487428 2025-06-30 0001487428 hrzn:The625NotesDue2027Member 2025-01-01 2025-12-31 0001487428 us-gaap:CommonStockMember 2025-01-01 2025-12-31 shares iso4217:USD FY 2025 --12-31 true 0001487428 NYSE 676-8654 10-K/A true 2025-12-31 false 814-00802 HORIZON TECHNOLOGY FINANCE CORPORATION DE 27-2114934 312 Farmington Avenue Farmington CT 06032 860 Common Stock, par value $0.001 per share HRZN NASDAQ 6.25% Notes due 2027 HTFC No No Yes Yes Accelerated Filer false false true false false 300000000 68428576 EXPLANATORY NOTE