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Third Quarter 2017 Earnings Presentation

November 7, 2017

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Safe Harbor

Caution Concerning Forward-Looking Statements Various remarks that the Company makes contain forward-looking statements regarding acquisitions, acquisition integration, growth, growth priorities or plans, new products and related investment, revenues, adjusted OIBDA, churn, seats, lines or accounts, average revenue per user, cost of telephony services, the Company’s share repurchase plan, new products and related investment, capital expenditures, and other statements that are not historical facts or information constitute forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. The forward-looking statements are based on information available at the time the statements are made and/or management's belief as of that time with respect to future events and involve risks and uncertainties that could cause actual results and outcomes to be materially different. Important factors that could cause such differences include but are not limited to: the competition we face; the expansion of competition in the cloud communications market; our ability to adapt to rapid changes in the cloud communications market; the nascent state of the cloud communications for business market; our ability to retain customers and attract new customers; the risk associated with developing and maintaining effective internal sales teams and effective distribution channels; risks related to the acquisition or integration of businesses we have acquired; security breaches and other compromises of information security; risks associated with sales of our services to medium-sized and enterprise customers; our reliance on third party hardware and software; our dependence on third party facilities, equipment, systems and services; system disruptions or flaws in our technology and systems; our ability to scale our business and grow efficiently; our dependence on third party vendors; the impact of fluctuations in economic conditions, particularly on our small and medium business customers; our ability to comply with data privacy and related regulatory matters; our ability to obtain or maintain relevant intellectual property licenses; failure to protect our trademarks and internally developed software; fraudulent use of our name or services; intellectual property and other litigation that have been and may be brought against us; reliance on third parties for our 911 services; uncertainties relating to regulation of VoIP services; risks associated with legislative, regulatory or judicial actions regarding our CPaaS products; the impact of governmental export controls or sanctions on our CPaaS products; our ability to establish and expand strategic alliances; risks associated with operating abroad; risks associated with the taxation of our business; risks associated with a material weakness in our internal controls; our dependence upon key personnel; governmental regulation and taxes in our international operations; liability under anti-corruption laws; our dependence on our customers' existing broadband connections; differences between our services and traditional telephone service; restrictions in our debt agreements that may limit our operating flexibility; foreign currency exchange risk; the market for our stock; our ability to obtain additional financing if required; any reinstatement of holdbacks by our credit card processors; our history of net losses and ability to achieve consistent profitability in the future; and other factors that are set forth in the “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2016, in the Company’s Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. While the Company may elect to update forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so, and therefore, you should not rely on these forward-looking statements as representing the Company's views as of any date subsequent to today. Non-GAAP Financial Measures This presentation contains non-GAAP financial measures (including adjusted operating income before depreciation and amortization (“adjusted OIBDA”), adjusted OIBDA less capex, adjusted net income, net debt (cash),free cash flow, organic growth and adjusted revenues), as defined in Regulation G adopted by the SEC. The Company provides a reconciliation of these non-GAAP financial measures to the most directly comparable financial measure at the end of the presentation and in the Company's quarterly earnings releases, which can be found on the Vonage Investor Relations website at http://ir.vonage.com.

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Recent Highlights

•  Grew total consolidated revenues to $253 million, the 10th consecutive quarter of year-over-year growth -  Grew Vonage Business revenues 21% organically year-over-year

-  Grew Nexmo revenues 45% organically year-over-year

•  Invested in Vonage Business growth initiatives -  UCaaS: Expanded to 20 field sales offices and hired new Channel Chief

-  CPaaS: Grew registered developers to over 300 thousand and expanded APAC presence with new sales offices

•  Continued optimization of Consumer services -  Reported customer churn of 1.9% and fourth consecutive quarter of lower year-over-year percentage revenue decline

-  Increased 2017 revenue guidance to over $500 million and 2021 allocated free cash flow projection to over $700 million

•  Delivered record Adjusted OIBDA of $51 million and Adjusted OIBDA - CAPEX of $42 million -  Paid down $37 million of debt, resulting in leverage of 1.7x LTM net debt to Adjusted OIBDA

•  Increased full year 2017 revenue guidance to at least $1.0 and as high as $1.005 billion and increased Adjusted OIBDA guidance to at least $180 million

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Representative Customers

Vonage is Driving UCaaS Service Revenue Growth Within Mid-Market AND Enterprise Segments

Strong Mid-market and Enterprise Presence Recent Mid-market and Enterprise Activity

UCaaS SaaS Integration

2,400 employee win due to:

SaaS Integration SmartWAN Contact Center

1,500 seat expansion due to:

UCaaS SmartWAN SaaS Integration

10,000 seat channel win due to:

Analytics SmartWAN and MPLS

1000+

250

50 Under 50 Seats

~40% of MRR Up-Market

- 999

Seats

-249

Seats

Seats

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Nexmo, the Vonage API Platform, Producing Strong Results

1.  Excludes unqualified developer signups 2.  Growth is organic. Adjusts for net-to-gross revenue reporting adjustment

176 207 249

309 371

3Q'16 4Q'16 1Q'17 2Q'17 3Q'17

(in 0

00's

)

Registered Developers1

$26

$38

3Q'16 3Q'17

($ in

mm

's)

CPaaS Revenues

45% YoY2

Customers & Partners

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Consolidated Revenues

•  GAAP Consolidated revenues up 2% from the prior year due to: -  Vonage Business organic growth

-  Offset by managed decline in Consumer

•  Vonage Business revenues represented 51% of total revenues -  Positioned for accelerating top-line growth

3Q'16 2Q'17 3Q'17

($ in millions)

$252 $253 $248 Business Consumer

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Segment Revenues

•  Vonage Business revenues up 22% GAAP from the prior year due to: –  UCaaS organic service revenue growth of 16%

–  CPaaS organic revenue growth of 45%

3Q'16 2Q'17 3Q'17

Service Product & USF

Business

Consumer

•  Consumer revenues decline improving due to: –  Lower Consumer customer churn

–  Strong Customer usage dynamics

–  Stable ARPU

$129 $124 $106

($ in millions)

3Q'16 2Q'17 3Q'17

Service Product & USF

$124 $128 $142

1.  Growth rate is organic. We define organic growth as the increase in Business revenues after giving pro forma effect for the acquisition of Nexmo, the change in accounting treatment with respect to certain CPaaS revenues being recognized on a gross rather than net basis and the exclusion of one-time items.

21% Organic YoY1

22% GAAP YoY

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Optimization of Consumer for Cash Flow Yielding Strong Results

14.6% 14.4%

14.0%

13.4%

12.9%

2.2% 2.2%

2.2%

1.9% 1.9%

12.5%

13.0%

13.5%

14.0%

14.5%

15.0%

Q3'16 Q4'16 Q1'17 Q2'17 Q3'17

Churn

YoY revenue decline %

Improving Consumer Trends •  Successful optimization of Consumer driven by: -  Historic-low Customer churn of 1.9%

-  Tenured customers1 increased to 81% of base

-  Stable ARPU

-  ~1.5 million subscribers

-  >95% of all customers are active users

-  Active users average more than 500 minutes per month

1.  Customers with Vonage for more than two years

Consumer expected to generate $700 million of allocated after tax FCF between 4Q 2017 and 2021

Consumer Customer Base

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Operating Expenses

•  Consolidated Sales & Marketing down from the prior year due to: –  Reduction in Consumer marketing

–  Offset by increased Business marketing

3Q'16 2Q'17 3Q'17

Sales & Marketing

General & Administrative

•  General and Administrative down from the prior year due to lower: –  Employee-related costs

–  Amortization of Nexmo deal consideration to employees

–  Bonus accrual

$74 $80 $84

($ in millions)

3Q'16 2Q'17 3Q'17

$27

$37

$28

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Operating Income and Adjusted OIBDA1

1.  This is a non-GAAP financial measure. Please refer to the end of the presentation for a reconciliation to GAAP income from operations.

($ in millions)

Income From Operations

Adjusted OIBDA1

•  Operating Income and Adjusted OIBDA up from the prior year due to: –  Lower S&M and G&A $15

$7

$25

3Q'16 2Q'17 3Q'17

$41 $41

$51

3Q'16 2Q'17 3Q'17

•  Operating Income and Adjusted OIBDA up sequentially due to: –  Lower S&M and G&A

–  Higher revenue at stable gross margin % driving higher gross profit

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Cash Flow and Balance Sheet

•  Cash: $30 million •  Total debt: $279 million •  Net debt1: $249 million (Gross Debt less Unrestricted Cash and Marketable Securities)

Net debt/Adjusted OIBDA = 1.7x

Cash Flow ($ in millions) Q3 2017 Cash from operations $48 Capital expenditures and software ($9) Free cash flow1 $39

Significant strategic and financial flexibility

Debt Repayment •  $37 million in debt repayment in Q3 2017 •  $56 million in debt repayment YTD through September

1.  This is a non-GAAP financial measure. Please refer to the end of the presentation for a reconciliation to GAAP income from operations.

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2017 Guidance

($ in Millions)

Prior Guidance Adjusted Guidance

Consolidated Revenues $981 to $996 At least $1,000; up to $1,005

Consumer Revenues $483 to $492 At least $500; up to $505

Business Revenues $498 to $504 No Change

Adjusted OIBDA At least $165 At least $180

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Business Revenues Reconciliation

($ in millions) Q3-16 Q4-16 Q1-17 Q2-17 Q3-17

GAAP total UCaaS revenues $82.4 $84.0 $85.6 $88.5 $90.9 Bad debt policy reclassification - - - - - Early termination fee - - - - - Accounts receivable write-down (0.3) 0.3 0.3 - -

Total UCaaS revenues incl. one-time items (Non-GAAP) $82.1 $84.3 $85.9 $88.5 $90.9

Hosted Infrastructure Business1 (1.6) (1.7) (1.6) (1.1) -

Adjusted total UCaaS Revenues (non-GAAP) $80.5 $82.6 $84.3 $87.4 $90.9 Product 13.6 12.7 13.4 13.4 13.1 USF 6.0 6.2 6.2 6.5 6.7 Adjusted total UCaaS Service Revenues (non-GAAP) $60.9 $63.8 $64.7 $67.6 $71.1

GAAP total CPaaS revenue $23.9 $26.5 $26.2 $35.2 $38.4 Nexmo pre-acquisition revenues Pro forma CPaaS revenues 23.9 26.5 26.2 35.2 38.4

Net-to-gross revenue reporting adjustment 2.5 2.8 3.4 - -

Adjusted total CPaaS revenues (non-GAAP) $26.4 $29.4 $29.6 $35.2 $38.4

GAAP Vonage Business revenues $106.3 $110.5 $111.8 $123.7 $129.3

1.  Hosted Infrastructure Business sold on June 1, 2017- revenues only reported through the date of sale

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Non-GAAP Reconciliation

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Non-GAAP Reconciliation

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Non-GAAP Reconciliation

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Non-GAAP Reconciliation