Company: DLX
Filing Date: 2025-03-10
Form Type: DEFA14A
Source: 0000027996-25-000108
Chunk: 0

Company: DELUXE CORP
Filing Date: 2025-03-10
Form: DEFA14A
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

#### SCHEDULE 14A
<div align='center'>Proxy Statement Pursuant to Section 14(a) of the Securities

Exchange Act of 1934 (Amendment No. )</div>

Filed by the Registrant x

Filed by a Party other than the Registrant ¨

Check the appropriate box:

¨ Preliminary Proxy Statement

¨ Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

¨ Definitive Proxy Statement

x Definitive Additional Materials

¨ Soliciting Material under §240.14a-12

| Deluxe Corporation                                                       |
| (Name of Registrant as Specified In Its Charter)                         |
| (Name of Person(s) Filing Proxy Statement, if Other Than the Registrant) |

| Payment of Filing Fee (Check the appropriate box): |     |                                                                                                     |
| x                                                  |     | No fee required.                                                                                    |
| ¨                                                  |     | Fee paid previously with preliminary materials:                                                     |
| ¨                                                  |     | Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11 |