SCHEDULE 13D/A

Custom Truck One Source Inc

Common Stock · CUSIP: 23204X103

Event date: 2024-12-19

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• ECP ControlCo, LLCReported CIK 0001707921

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III, LLC

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners GP III, LP

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III, LP

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III-A, LP

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III-B, LP

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III-C, LP

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III-D, LP

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners GP III Co-Investment (NESCO), LLC

  Shares: 16,287,270.00 · Class: 7.0%

• Energy Capital Partners III (NESCO Co-Invest), LP

  Shares: 16,287,270.00 · Class: 7.0%

• ECP Starlight Public GP, LLC

  Shares: 16,287,270.00 · Class: 7.0%

• ECP Starlight Guarantor (Public), LP

  Shares: 16,287,270.00 · Class: 7.0%

• NESCO Holdings GP, LLC

  Shares: 16,287,270.00 · Class: 7.0%

• NESCO Holdings, LP

  Shares: 13,439,824.00 · Class: 5.8%

• ECP Cardinal Holdings, LP

  Shares: 2,847,446.00 · Class: 1.2%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.