Exhibit 99.1 ACI Worldwide, Inc. Reports Financial Results for the Quarter Ended March 31, 2024 Q1 2024 HIGHLIGHTS • Revenue up 9% versus Q1 2023 • Net income (loss) improved $24 million over Q1 2023 to a loss of $8 million • Adjusted EBITDA up 93% versus Q1 2023 • Cash flow from operating activities up 208% versus Q1 2023 • Repurchased 2 million shares for $63 million • Raising guidance range for full-year 2024 Omaha, NE — April 30, 2024 — ACI Worldwide (NASDAQ: ACIW), a global leader in mission-critical, ...