0001213900-23-075020.txt : 20230907 0001213900-23-075020.hdr.sgml : 20230907 20230907164217 ACCESSION NUMBER: 0001213900-23-075020 CONFORMED SUBMISSION TYPE: 144 PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 20230907 DATE AS OF CHANGE: 20230907 SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: Custom Truck One Source, Inc. CENTRAL INDEX KEY: 0001709682 STANDARD INDUSTRIAL CLASSIFICATION: SERVICES-EQUIPMENT RENTAL & LEASING, NEC [7359] IRS NUMBER: 000000000 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: 144 SEC ACT: 1933 Act SEC FILE NUMBER: 001-38186 FILM NUMBER: 231242759 BUSINESS ADDRESS: STREET 1: 7701 INDEPENDENCE AVENUE CITY: KANSAS CITY STATE: MO ZIP: 64125 BUSINESS PHONE: (816) 241-4888 MAIL ADDRESS: STREET 1: 7701 INDEPENDENCE AVENUE CITY: KANSAS CITY STATE: MO ZIP: 64125 FORMER COMPANY: FORMER CONFORMED NAME: NESCO HOLDINGS, INC. DATE OF NAME CHANGE: 20190730 FORMER COMPANY: FORMER CONFORMED NAME: Capitol Investment Corp. IV DATE OF NAME CHANGE: 20170619 REPORTING-OWNER: COMPANY DATA: COMPANY CONFORMED NAME: Energy Capital Partners Management, LP CENTRAL INDEX KEY: 0001815150 IRS NUMBER: 000000000 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: 144 BUSINESS ADDRESS: STREET 1: 51 JOHN F. KENNEDY PARKWAY STREET 2: SUITE 200 CITY: SHORT HILLS STATE: NJ ZIP: 07078 BUSINESS PHONE: (973) 671-6100 MAIL ADDRESS: STREET 1: 51 JOHN F. KENNEDY PARKWAY STREET 2: SUITE 200 CITY: SHORT HILLS STATE: NJ ZIP: 07078 144 1 primary_doc.xml 144 0001815150 XXXXXXXX LIVE 0001709682 Custom Truck One Source, Inc. 001-38186 7701 Independence Ave. Kansas City MO 64125 816-241-4888 Energy Capital Partners Management, LP Stockholder Common Stock J.P. Morgan Securities LLC

Attn: Restricted Stock Team 390 Madison Avenue - 6th Floor New York NY 10017

135094 903778.86 246262581 09/07/2023 NYSE Common Stock 04/01/2021 Vesting of restricted stock unit award Issuer N 60000 04/01/2021 None Common Stock 05/17/2021 Stock option exercise Issuer N 47148 05/17/2021 Net Settlement Common Stock 04/01/2022 Vesting of restricted stock unit award Issuer N 13631 04/01/2022 None Common Stock 03/31/2023 Vesting of restricted stock unit award Issuer N 14315 03/31/2023 None Y Represents securities to be sold by Energy Capital Partners Management, LP, which were acquired as director compensation. No securities reported herein are being sold by NESCO Holdings, LP or ECP Cardinal Holdings, LP. 09/07/2023 Energy Capital Partners Management, LP, By: ECP Management GP, LLC, By: ECP ControlCo, LLC, By: /s/ Rahman D'Argenio, Managing Member