Vertex, Inc.

All statements made in this Quarterly Report on Form 10-Q that are not statements of historical fact, including statements about our beliefs and expectations and regarding future events or our future results of operations, financial condition, business, strategies, financial needs, the plans and objectives of management, and our stock repurchase program are forward-looking statements and should be evaluated as such.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

Significant estimates used in preparing these condensed consolidated financial statements include: (i) the estimated allowance for subscription cancellations; (ii) expected credit losses associated with the allowance for doubtful accounts; (iii) allowance for credit losses on available-for-sale debt securities; (iv) the reserve for self-insurance; (v) assumptions related to achievement of technological feasibility for software developed for sale; (vi) product life cycles; (vii) estimated 11 Table of Contents ) Vertex, Inc.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

Purchase Consideration Total purchase consideration for the Acquisition was $ 22,070 net of $ 40 cash acquired, which included $ 10,089 for the settlement of pre-existing debt/borrowings.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

The carrying amount of the Company s bank debt approximates fair value as the variable rates on the debt approximate those commercially available in the market and is considered a Level 3 measurement.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

For further information on the Notes, refer to Note 8, Debt .

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

Forward-looking statements include information concerning possible or assumed future results of operations, including descriptions of our business plan and strategies.

SEC original ↗Vertex, Inc. — Earnings release (8-K exhibit)EX-99Aug 6, 2025

Because we recognize subscription revenues ratably, we believe investors can use ARR to measure our expansion of existing customer revenues, new customer activity, and as an indicator of future software subscription revenues.

SEC original ↗Vertex, Inc. — Earnings release (8-K exhibit)EX-99Aug 6, 2025

We also believe it demonstrates to investors our ability to expand existing customer revenues, which is one of our key growth strategies.

SEC original ↗Vertex, Inc. — Earnings release (8-K exhibit)EX-99Aug 6, 2025

Our NRR refers to the ARR expansion during the 12 months of a reporting period for all direct customers who were part of our customer base at the beginning of the reporting period.

SEC original ↗Vertex, Inc. — Earnings release (8-K exhibit)EX-99Aug 6, 2025

Our NRR calculation takes into account any revenues lost from departing direct customers or those who have downgraded or reduced usage, as well as any revenue expansion from migrations, new licenses for additional products or contractual and usage-based price changes.

SEC original ↗Vertex, Inc. — Earnings release (8-K exhibit)EX-99Aug 6, 2025

Given the number of risk factors, uncertainties and assumptions discussed below, actual results may differ materially.

SEC original ↗Vertex, Inc. — Earnings release (8-K exhibit)EX-99Aug 6, 2025

Legal Proceedings 64 Item 1A.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

The forward-looking statements are subject to and involve risks, uncertainties and assumptions, and you should not place undue reliance on these forward-looking statements.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

4 Table of Contents The risks included here are not exhaustive, and additional factors could adversely affect our business and financial performance, including factors and risks included in our Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission (the SEC ) on February 24, 2026 (the 2025 Annual Report ).

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026

Given these risks and uncertainties, you should not place undue reliance on our forward-looking statements, and you should not rely on forward-looking statements as predictions of future events.

SEC original ↗Vertex, Inc. — 10-Q Quarterly report10-QAug 4, 2026