Insight Enterprises (NSIT) Proxy filing summary

Voting matters and shareholder proposals

• Number of common shares outstanding and entitled to vote at the 2026 Annual Meeting corrected to 30,361,891, an increase of 283,621 shares due to an administrative error.

• Proxy voting instructions already submitted remain valid unless shareholders choose to change their vote.

Shareholder rights and capital structure

• Correction to the number of shares outstanding directly impacts the voting power and quorum calculations for the Annual Meeting.

Executive summary

• Supplement amends the definitive proxy statement to correct the number of shares outstanding and entitled to vote at the 2026 Annual Meeting.

• No other disclosures in the proxy statement are modified or updated by this supplement.