Reliant Bancorp : United Community Banks, Inc. and Reliant Bancorp, Inc. Acquisition Presentation

Acquisition of Reliant Bancorp, Inc.

Entering Nashville MSA and

Strengthening Our Tennessee Franchise

July 14, 2021

Important Information For Stockholders and Investors

This presentation relates to a proposed merger of United Community Banks, Inc. ("United") and Reliant Bancorp, Inc. ("Reliant"). In connection with the proposed merger, United is required to file with the Securities and Exchange Commission ("SEC") a registration statement on Form S-4 that will include a Proxy Statement of Reliant to be sent to Reliant's stockholders seeking their approval of the merger. The registration statement also will contain the prospectus of United to register the shares of United common stock to be issued in connection with the merger. A definitive proxy statement/prospectus will also be provided to Reliant's stockholders as required by applicable law. INVESTORS AND STOCKHOLDERS OF RELIANT ARE ENCOURAGED TO READ THE REGISTRATION STATEMENT, INCLUDING THE PROXY STATEMENT/PROSPECTUS THAT WILL BE A PART OF THE REGISTRATION STATEMENT WHEN IT BECOMES AVAILABLE AND ANY OTHER RELEVANT DOCUMENTS FILED BY UNITED OR RELIANT WITH THE SEC, INCLUDING ANY AMENDMENTS OR SUPPLEMENTS TO THE REGISTRATION STATEMENT AND THOSE OTHER DOCUMENTS, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT UNITED, RELIANT AND THE PROPOSED TRANSACTION.

The registration statement and other documents filed with the SEC may be obtained for free at the SEC's website (www.sec.gov). You will also be able to obtain these documents, free of charge, from United at the "Investor Relations" section of United's website at www.UCBI.com or from Reliant at the "Investors" section of Reliant's website at www.reliantbank.com. Copies of the definitive proxy statement/prospectus will also be made available, free of charge, by contacting United Community Banks, Inc., P.O. Box 398, Blairsville, GA 30514, Attn: Jefferson Harralson, Telephone: [phone], or Reliant Bancorp, Inc., 6100 Tower Circle, Suite 120, Franklin TN 37067, Attn: Jerry Cooksey, Telephone: [phone].

This communication does not constitute an offer to sell, the solicitation of an offer to sell or the solicitation of an offer to buy securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such jurisdiction. This communication is also not a solicitation of any vote or approval with respect to the proposed transactions or otherwise.

PARTICIPANTS IN THE TRANSACTION

United and Reliant and certain of their respective directors and executive officers, under the rules of the SEC, may be deemed to be participants in the solicitation of proxies from Reliant's stockholders in favor of the approval of the proposed merger. Information about the directors and officers of United and their ownership of United common stock can also be found in United's definitive proxy statement in connection with its 2021 annual meeting of shareholders, as filed with the SEC on March 30, 2021, and other documents subsequently filed by United with the SEC. Information about the directors and executive officers of Reliant and their ownership of Reliant capital stock, as well as information regarding the interests of other persons who may be deemed participants in the transaction, may be found in Reliant's definitive proxy statement in connection with its 2021 annual meeting with shareholders, as filed with the SEC on April 8, 2021, and other documents subsequently filed and also may be obtained by reading the Proxy Statement/Prospectus regarding the proposed merger when it becomes available. Free copies of this document may be obtained as described above..

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Cautionary Statement About Forward-Looking Statements

This communication contains "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In general, forward-looking statements usually may be identified through use of words such as "may," "believe," "expect," "anticipate," "intend," "will," "should," "plan," "estimate," "predict," "continue" and "potential" or the negative of these terms or other comparable terminology, and include statements related to the expected timing of the closing of the merger, the expected returns and other benefits of the merger to stockholders, expected improvement in operating efficiency resulting from the merger, estimated expense reductions resulting from the transactions and the timing of achievement of such reductions, the impact on and timing of the recovery of the impact on tangible book value, and the effect of the merger on United's capital ratios. Forward-looking statements are not historical facts and represent management's beliefs, based upon information available at the time the statements are made, with regard to the matters addressed; they are not guarantees of future performance. Actual results may prove to be materially different from the results expressed or implied by the forward-looking statements. Forward-looking statements are subject to numerous assumptions, risks and uncertainties that change over time and could cause actual results or financial condition to differ materially from those expressed in or implied by such statements.

Factors that could cause or contribute to such differences include, but are not limited to (1) the risk that the cost savings and any revenue synergies from the merger may not be realized or take longer than anticipated to be realized, (2) disruption from the merger with customer, supplier, employee or other business partner relationships, (3) the occurrence of any event, change or other circumstances that could give rise to the termination of the merger agreement, (4) the failure to obtain the necessary approval by the stockholders of Reliant, (5) the possibility that the costs, fees, expenses and charges related to the merger may be greater than anticipated, (6) the ability by United to obtain required governmental approvals of the merger, (7) reputational risk and the reaction of each of the companies' customers, suppliers, employees or other business partners to the merger, (8) the failure of the closing conditions in the merger agreement to be satisfied, or any unexpected delay in closing the merger, (9) the risks relating to the integration of Reliant's operations into the operations of United, including the risk that such integration will be materially delayed or will be more costly or difficult than expected, (10) the risk of potential litigation or regulatory action related to the merger, (11) the risks associated with United's pursuit of future acquisitions, (12) the risk of expansion into new geographic or product markets, (13) the dilution caused by United's issuance of additional shares of its common stock in the merger, and (14) general competitive, economic, political and market conditions. Further information regarding additional factors which could affect the forward-looking statements can be found in the cautionary language included under the headings "Cautionary Note Regarding Forward-Looking Statements" and "Risk Factors" in United's Annual Report on Form 10-K for the year ended December 31, 2020, and other documents subsequently filed by United with the SEC.

Many of these factors are beyond United's and Reliant's ability to control or predict. If one or more events related to these or other risks or uncertainties materialize, or if the underlying assumptions prove to be incorrect, actual results may differ materially from the forward-looking statements. Accordingly, stockholders and investors should not place undue reliance on any such forward-looking statements. Any forward-looking statement speaks only as of the date of this communication, and neither United nor Reliant undertakes any obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. New risks and uncertainties may emerge from time to time, and it is not possible for United or Reliant to predict their occurrence or how they will affect United or Reliant.

United and Reliant qualify all forward-looking statements by these cautionary statements.

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Transaction Highlights

Expansion into Nashville MSA, one of the top markets in the Southeast

Strengthens Tennessee

Franchise

Financially Compelling and

Poised for Growth

Strong Cultural Fit

Consistent M&A Strategy

• $3 billion community bank with top 10 market share in the Nashville, MSA
• • Recognized by Raymond James for performing in the top 10% of domestic community banks
  • One of two Tennessee banks recognized by S&P Global Market Intelligence as a top performing community bank out of 4,287 banks with under $3 billion in assets
  • 6th fastest growing MSA in the Southeast (1)
  • 6th largest metro in the Southeast
• Pro forma top 10 deposit market share in Tennessee
• Mid-singledigit EPS % accretion in 2022; high single-digit EPS % accretion in 2023 (first full year of cost savings recognition)
• IRR greater than 25%
• Improves efficiency ratio by 350+ bps and ROTCE by ~135 bps (first full year of cost savings realization)
• Manageable tangible book value dilution and earnback period of approximately 3 years
• No revenue synergies projected, but opportunity to leverage Reliant's commercial relationships through United's diversified platform and larger balance sheet
• Gaining talented Tennessee leadership team, led by DeVan Ard's nearly 40 years of banking experience and knowledge of the Nashville marketplace
• Relationship-orientedbank centered on delivering excellent customer service and recognized as the best community bank in Tennessee by Newsweek
• Multiple years of recognition as a top workplace
• Transaction consistent with United's strategy of acquiring high-quality,franchise-enhancing companies in growth markets
• Highly experienced acquirer with a long track record of successfully integrating whole-bank transactions
• Conservative assumptions supported by extensive due diligence

Note: Financial data as of March 31, 2021; deposit market share and demographic data as of June 30, 2020

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1. Based on projected population growth between 2021-2026 of MSAs with a population greater than 1,000,000 Source: S&P Global Market Intelligence; company documents, Reliant investor relations website

Preliminary Transaction Assumptions

Consideration

Transaction Metrics

Pro Forma Ownership

Cost Savings

One-Time Expenses

Credit / Interest Marks

Financial Impacts and

Returns

Expected Closing

• 0.9842 shares of United common stock to be issued for each share of Reliant common stock
• Aggregate transaction value (1) of $517 million
• • Aggregate consideration includes $7.1 million for restricted stock awards and units, and $1.2 million for stock options
• Transaction value per share (1) of $30.58

	Aggregate Price-to-Tangible Book Value:	194.1%
	Aggregate Price-to-LTM Net Income:	11.8x
 Aggregate Price-to-2022E Net Income after Cost Savings (2) :	8.3x
	Core Deposit Premium	12.1%
 Market Price Premium (3):	11.0%

• 84% United / 16% Reliant
• Issuing 16,606,718 shares to Reliant common shareholders
• 31% of Reliant's 2022 estimated adjusted non-interest expense (4)
• • 75% realization of cost savings in 2022, and 100% in years thereafter
• $34.0 million of pre-taxone-time expenses (6.6% of transaction value)
• Total gross credit marks of $63.1 million; or 2.6% of total loans (ex-PPP)
• • Day 1 gross credit mark of $44.8 million or 1.9% of loans (ex-PPP); 1.0% net of Reliant's $20.8 million loan loss reserve
  • • $13.9 million non-PCD; $30.9 million PCD
  • Day 2 estimated allowance related to CECL of $15.7 million
  • Additional $2.5 million reserve for unfunded commitments
• Positive gross interest rate mark of $2.8 million, or 0.12% of total loans (ex-PPP)
• Expected to be $0.15 per share (6.1%) accretive to EPS in 2022 and $0.22 per share (8.5%) in 2023 (first full year of cost savings recognition)
• Anticipated initial tangible book value dilution of $0.70, or 3.7%, and a ~3 year earn back period
• Estimated pro forma leverage ratio at transaction close of 9.5%
• Early Q1 2022

1.	Based on United's closing stock price of $31.07 as of the market close on July 13, 2021, and value of the stock options and restricted stock units	5
2.	Metric includes 100% realization of projected annual after-tax cost savings

1. Based on Reliant's stock price of $27.54 as of July 13, 2021
2. Adjusted non-interest expense excludes Reliant's mortgage operations