Company: SFNC
Filing Date: 2025-09-10
Form Type: 424B5
Source: 0001193125-25-200113
Chunk: 12

Company: SIMMONS FIRST NATIONAL CORP
Filing Date: 2025-09-10
Form: 424B5
Chunk 12
---

 by the Term SOFR Administrator at the Reference Time for any floating rate interest period, as determined by the calculation agent after giving effect to the Three-Month Term SOFR Conventions (each as defined under “Description of the Notes 
 — Interest”).                                                                                                                                                                                                                                    |

| If the calculation agent determines on or prior to the relevant Reference Time that a Benchmark Transition Event and its related Benchmark Replacement Date (each as defined under “Description of the Notes —                                            
 Interest”) have occurred with respect to Three-Month Term SOFR, then the provisions under “Description of the Notes — Effect of Benchmark Transition Event,” which are referred to herein as the “benchmark transition                                    
 provisions,” will thereafter apply to all determinations of the interest rate on the Notes for each interest period occurring after the applicable Benchmark Transition Event and its related Benchmark Replacement Date during the floating rate         
 period. In accordance with the benchmark transition provisions, after a Benchmark Transition Event and its related Benchmark Replacement Date have occurred, the interest rate on the Notes for each interest period during the floating rate period will 
 be an annual rate equal to the Benchmark Replacement (as defined under “Description of the Notes”) plus 302 basis points.                                                                                                                                 |

S-7

| Record Dates | Interest on each Note will be payable to the person in whose name such Note is registered on the 15th day immediately preceding the applicable interest payment date. |

| Day Count Convention | Fixed rate period: 360-day year consisting of twelve 30-day months. |

| Floating rate period: 360-day year and the actual number of days elapsed in each interest period (or any other relevant period). |

| No Guarantee | The Notes will not be guaranteed by any of our subsidiaries. As a result, the Notes will be structurally subordinated to the liabilities of our subsidiaries as discussed below under “Ranking; Subordination.” |

| • |     | will rank junior in right of payment and upon our liquidation to any of our existing and all future Senior 
 Indebtedness (as defined in the Indenture), all as described under “Description of the Notes”;             |

| • |     | will rank junior in right of payment and upon our liquidation to any of our future general creditors; |

| • |     | will rank equal in right of payment and upon our liquidation with all of our future indebtedness the terms of                                                                        
 which provide that such indebtedness ranks equally with promissory notes, bonds, debentures and other evidences of indebtedness of types that include