<SEC-DOCUMENT>0001213900-21-020238-index.html : 20210405
<SEC-HEADER>0001213900-21-020238.hdr.sgml : 20210405
<ACCEPTANCE-DATETIME>20210405202158
ACCESSION NUMBER:		0001213900-21-020238
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210401
FILED AS OF DATE:		20210405
DATE AS OF CHANGE:		20210405

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ECP ControlCo, LLC
		CENTRAL INDEX KEY:			0001707921
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38186
		FILM NUMBER:		21807720

	BUSINESS ADDRESS:	
		STREET 1:		40 BEECHWOOD ROAD
		CITY:			SUMMIT
		STATE:			NJ
		ZIP:			07901
		BUSINESS PHONE:		(973) 671-6100

	MAIL ADDRESS:	
		STREET 1:		40 BEECHWOOD ROAD
		CITY:			SUMMIT
		STATE:			NJ
		ZIP:			07901

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Energy Capital Partners Management, LP
		CENTRAL INDEX KEY:			0001815150
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38186
		FILM NUMBER:		21807718

	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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ECP Management GP, LLC
		CENTRAL INDEX KEY:			0001815147
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38186
		FILM NUMBER:		21807719

	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

ISSUER:		

	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

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<TEXT>
Document 1 - file: ownership.html

Document 1 - RAW XML: ownership.xml

</DOCUMENT>
</SEC-DOCUMENT>