# EDGAR Filing Document

**Accession Number:** 0001979330
**File Stem:** 9999999995-25-002411
**Filing Date:** 2025-7
**Character Count:** 1237
**Document Hash:** 660ffb1ec83cbf05f1bbdd448afe9cce
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**9999999995-25-002411.hdr.sgml**: 20250731

**ACCESSION NUMBER**: 9999999995-25-002411

**CONFORMED SUBMISSION TYPE**: EFFECT

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250730

**DATE AS OF CHANGE**: 20250731

**EFFECTIVENESS DATE**: 20250730

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** NB Bancorp, Inc.
- **CENTRAL INDEX KEY:** 0001979330
- **STANDARD INDUSTRIAL CLASSIFICATION:** SAVINGS INSTITUTIONS, NOT FEDERALLY CHARTERED [6036]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 932560883
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** EFFECT
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-288494
- **FILM NUMBER:** 251169102

**BUSINESS ADDRESS:**
- **STREET 1:** 1063 GREAT PLAIN AVENUE
- **CITY:** NEEDHAM
- **STATE:** MA
- **ZIP:** 02492
- **BUSINESS PHONE:** 781-444-2100

**MAIL ADDRESS:**
- **STREET 1:** 1063 GREAT PLAIN AVENUE
- **CITY:** NEEDHAM
- **STATE:** MA
- **ZIP:** 02492

### UNITED STATES
### SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## Notice of Effectiveness

**Date:** July 30, 2025

**Time:** 09:00:00

**Form Type:** S-4

---

**CIK:** 0001979330

**Company Name:** NB Bancorp, Inc.

**File Number:** 333-288494