X0202 SCHEDULE 13G 0002142636 XXXXXXXX LIVE Class A common stock, $1.00 par value per share 07/15/2026 0001901637 USCB Financial Holdings, Inc. 90355N101 2301 N.W. 87th Avenue Doral FL 33172 Rule 13d-1(c) Inversiones Atlantida S.A. K2 0 1500000 0 1500000 1500000 N 8.2 CO Atlantida Corporation Limited X0 0 1500000 0 1500000 1500000 N 8.2 CO HC Guillermo Bueso Anduray K2 0 1500000 0 1500000 1500000 N 8.2 IN USCB Financial Holdings, Inc. 2301 N.W. 87th Avenue Doral, FL 33172 This Schedule 13G is filed by the following (each a "Reporting Person" and collectively the "Reporting Persons"): (i) Inversiones Atlantida S.A., a Honduras company ("Invatlan"); (ii) Atlantida Corporation Limited, a private limited company organized under the laws of England and Wales ("ACL"); and (iii) Guillermo Bueso Anduray ("Mr. Bueso Anduray"). The principal business address of Invatlan and Mr. Bueso Anduray is Plaza Bancatan, Centroamerica Blvd., Tegucigalpa, Francisco Morazan, Honduras. The principal business address of ACL is 27 Old Gloucester Street, London, United Kingdom, WC1N 3AX. See responses to Row 4 on each cover page. Y See responses to Row 9 on each cover page. Invatlan directly holds 1,500,000 shares of Class A common stock, $1.00 par value per share (the "Class A Shares") of USCB Financial Holdings, Inc. (the "Issuer"). ACL is the majority owner of Invatlan and Mr. Bueso Anduray is the Chief Executive Officer of Invatlan and has ultimate decision-making authority at certain entities that collectively have a majority ownership of ACL. As a result, each of ACL and Mr. Bueso Anduray may be deemed the beneficial owner of the securities beneficially owned by Invatlan. However, in accordance with Rule 13d-4 under the Securities Exchange Act of 1934, as amended, Mr. Bueso Anduray disclaims beneficial ownership of the securities beneficially owned by Invatlan or ACL. See responses to Row 11 on each cover page. All beneficial ownership percentages reported herein are calculated based on 18,263,900 Class A Shares outstanding as of April 30, 2026 as reported in the Quarterly Report on Form 10-Q filed by the Issuer on May 8, 2026. See responses to Row 5 on each cover page. See responses to Row 6 on each cover page. See responses to Row 7 on each cover page. See responses to Row 8 on each cover page. Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Exhibit 1 - Joint Filing Agreement Inversiones Atlantida S.A. /s/ Guillermo Bueso Anduray 07/17/2026 Atlantida Corporation Limited /s/ Guillermo Bueso Anduray 07/17/2026 /s/ Walter Bodden Joya 07/17/2026 Guillermo Bueso Anduray /s/ Guillermo Bueso Anduray 07/17/2026