SCHEDULE 13G 0001583223 XXXXXXXX LIVE Voting Common Stock 07/01/2025 0001297107 CoastalSouth Bancshares, Inc. 19058X207 400 GALLERIA PKWY, Suite 1900 ATLANTA GA 30339 Rule 13d-1(d) Patriot Financial Partners II, L.P. a DE 0.00 636988.00 0.00 636988.00 636988.00 N 7.86 PN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. Patriot Financial Partners II Coastal SPV, LLC a DE 0.00 711311.00 0.00 711311.00 711311.00 N 8.77 OO This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. Patriot Financial Partners Parallel II, L.P. a DE 0.00 74323.00 0.00 74323.00 74323.00 N 0.92 PN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. Patriot Financial Partners GP II, L.P. a DE 0.00 711311.00 0.00 711311.00 711311.00 N 8.77 PN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. Patriot Financial Partners GP II, LLC a DE 0.00 711311.00 0.00 711311.00 711311.00 N 8.77 OO This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. Patriot Financial Manager, L.P. a DE 0.00 7900.00 0.00 7900.00 7900.00 N 0.10 IA PN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. Patriot Financial Manager, LLC a DE 0.00 7900.00 0.00 7900.00 7900.00 N 0.10 OO This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. W. Kirk Wycoff a X1 0.00 719211.00 0.00 719211.00 719211.00 N 8.87 IN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. James J. Lynch a X1 0.00 719211.00 0.00 719211.00 719211.00 N 8.87 IN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. IRA M. LUBERT a X1 0.00 719211.00 0.00 719211.00 719211.00 N 8.87 IN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. JAMES F. DEUTSCH a X1 0.00 719211.00 0.00 719211.00 719211.00 N 8.87 IN This calculation is based on 8,106,892 shares of Voting Common Stock of the Issuer outstanding as of June 30, 2025, as reported in the Issuer's Form 10-Q filed on August 11, 2025. CoastalSouth Bancshares, Inc. 400 GALLERIA PKWY, Suite 1900 ATLANTA, GA, 30339 Patriot Financial Partners II, L.P. Patriot Financial Partners II Coastal SPV, LLC Patriot Financial Partners Parallel II, L.P. Patriot Financial Partners GP II, L.P. Patriot Financial Partners GP II, LLC Patriot Financial Manager, L.P. Patriot Financial Manager, LLC W. Kirk Wycoff James J. Lynch Ira M. Lubert James F. Deutsch Four Radnor Corporate Center 100 Matsonford Road Suite 210 Radnor, Pennsylvania 19087 See appropriate cover page above. Y See cover sheets above with respect to each of the reporting persons. The event requiring the filing by the reporting persons is the initial public offering of the Issuer which occurred on July 1, 2025. The reporting persons did not acquire any shares of voting common stock in the initial public offering and have not acquired any shares of voting common stock since the initial public offering was completed. The percentages do not reflect the effect of the issuance by the Issuer of shares of voting common stock in the initial public offering. See cover sheets above with respect to each of the reporting persons. NA See cover sheets above with respect to each of the reporting persons. NA See cover sheets above with respect to each of the reporting persons. Y Y Y N Patriot Financial Partners II, L.P. Patriot Financial Partners II Coastal SPV, LLC Patriot Financial Partners Parallel II, L.P. Patriot Financial Partners GP II, L.P. Patriot Financial Partners GP II, LLC Patriot Financial Manager, L.P. Patriot Financial Manager, LLC W. Kirk Wycoff James J. Lynch Ira M. Lubert James F. Deutsch Y Y The joint filing agreement dated as of September 16, 2025 by and among Patriot Financial Partners II, L.P., Patriot Financial Partners II Coastal SPV, LLC, Patriot Financial Partners Parallel II, L.P., Patriot Financial Partners GP II, L.P., Patriot Financial Partners GP II, LLC, Patriot Financial Manager, L.P., Patriot Financial Manager, LLC, W. Kirk Wycoff, James J. Lynch, Ira M. Lubert and James F. Deutsch is filed as Exhibit 1 hereto. Patriot Financial Partners II, L.P. /s/ W. Kirk Wycoff 09/16/2025 Patriot Financial Partners II Coastal SPV, LLC /s/ W. Kirk Wycoff 09/16/2025 Patriot Financial Partners Parallel II, L.P. /s/ W. Kirk Wycoff 09/16/2025 Patriot Financial Partners GP II, L.P. /s/ W. Kirk Wycoff 09/16/2025 Patriot Financial Partners GP II, LLC /s/ W. Kirk Wycoff 09/16/2025 Patriot Financial Manager, L.P. /s/ W. Kirk Wycoff 09/16/2025 Patriot Financial Manager, LLC /s/ W. Kirk Wycoff 09/16/2025 W. Kirk Wycoff /s/ W. Kirk Wycoff 09/16/2025 James J. Lynch /s/ James J. Lynch 09/16/2025 IRA M. LUBERT /s/ Ira M. Lubert 09/16/2025 JAMES F. DEUTSCH /s/ James F. Deutsch 09/16/2025