TWILIO INC

APPENDIX B

NON-GAAP Financial Measures

Non-GAAP Financial Measures

In addition to financial information presented in accordance with U.S. generally accepted accounting principles (“GAAP”), this proxy statement includes certain non-GAAP financial measures described below. We use these non-GAAP financial measures to evaluate our ongoing operations, for internal planning and forecasting purposes, and to set targets for our employee compensation programs. These non-GAAP financial measures are presented for supplemental informational purposes only, should not be considered substitutes for financial information presented in accordance with GAAP, and may be different from similarly-titled non-GAAP measures used by other companies.

Non-GAAP Income (Loss) from Operations

For the periods presented, we define non-GAAP income (loss) from operations (which is also referred to as “non-GAAP operating profit” and “non-GAAP operating income”) as GAAP income (loss) from operations adjusted to exclude, as applicable, stock-based compensation, amortization of acquired intangibles, loss on net assets divested, acquisition and divestiture related expenses, payroll taxes related to stock-based compensation, charitable contributions, restructuring costs, and impairment of long-lived assets. Segment-level non-GAAP income (loss) from operations is calculated using the same methodology, but using (and excluding, as applicable) only revenue and expenses attributable to the applicable segment.

Organic Revenue

For the periods presented, we define organic revenue as GAAP revenue, excluding (i) revenue from each acquired business and revenue from application-to-person (“A2P”) 10DLC fees imposed by major U.S. carriers on our core messaging business, in each case until the beginning of the first full quarter following the one-year anniversary of the closing date of such acquisition or the initial date such fees were charged and (ii) revenue from each divested business beginning in the quarter of the closing date of such divestiture; provided that (a) if an acquisition closes or such fees are initially charged on the first day of a quarter, such revenue will be included in organic revenue beginning on the one-year anniversary of the closing date of such acquisition or the initial date such fees were charged and (b) if a divestiture closes on the last day of a quarter, such revenue will be included in organic revenue for that quarter. A2P 10DLC fees are fees imposed by U.S. mobile carriers for A2P SMS messages delivered to its subscribers, and we pass these fees to our messaging customers at cost. Segment-level organic revenue is calculated using the same methodology, but using (and excluding, as applicable) only revenue attributable to the applicable segment.

Organic Revenue Growth

For the periods presented, we calculate organic revenue growth by dividing (i) organic revenue for the period presented less organic revenue in the corresponding period in the prior year by (ii) organic revenue in the corresponding period in the prior year. If revenue from certain acquisitions, divestitures or A2P 10DLC fees is included in organic revenue in the period presented, then revenue from the same acquisitions, divestitures and A2P 10DLC fees is included in organic revenue in the corresponding period in the prior year for purposes of the denominator in the organic revenue growth calculation. As a result, the denominator used in this calculation will not always equal the organic revenue reported for the prior period. Segment-level organic revenue growth is calculated using the same methodology, but using (and excluding, as applicable) only revenue attributable to the applicable segment.

Free Cash Flow

For the periods presented, we calculate free cash flow as net cash provided by (used in) operating activities, excluding capitalized software development costs and purchases of long-lived and intangible assets.

Reconciliation of Non-GAAP Financial Measures to GAAP

Non-GAAP Income (Loss) from Operations to Income (Loss) from Operations

Organic Revenue and Organic Revenue Growth to Revenue and Revenue Growth

Communications Organic Revenue and Communications Organic Revenue Growth to Communications Revenue and Communications Revenue Growth

Free Cash Flow to Net Cash Provided by (Used In) Operating Activities

Segment Operating Results