The implementation of new tax credit registration requirements for home HVAC systems by the IRS and Treasury is gradually taking shape, according to a senior industry official. Manufacturers are now able to register for the first component of a planned identification system.
“On February 4, they opened up their qualified manufacturer portal,” explained Samantha Slater, senior vice president of government affairs at the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). This allows manufacturers to “receive a four-digit qualified manufacturer number, which is part of the first four digits of the 17-digit PIN that Treasury and IRS proposed.”
The development marks a significant first step in implementing the Section 25C homeowner energy efficiency tax incentive requirements. However, Slater emphasized that for the upcoming tax season, only these initial four digits will be required.
The Treasury Department and IRS have released multiple guidance documents over the past year, including an October 2024 proposed rule and a January 17, 2025 FAQ document. Yet Slater notes that none of these constitutes final guidance or rules.
“We want to be able to make sure that [homeowners] have everything they need,” Slater said, acknowledging that while the 2026 tax season may seem distant, “people are already purchasing equipment that qualifies.”
AHRI, which represents HVACR and water heating manufacturers, has proposed solutions and adapted its product directory system in anticipation of future requirements. However, Slater indicates the industry remains in ongoing discussions about implementation as they await definitive guidance from federal authorities.
A Timeline of Development
The rollout of new identification requirements for HVAC tax credits has followed a complex path, with multiple regulatory steps throughout 2024 and early 2025, further complicated by a transition to a new administration, according to industry officials and government documents.
“The brief history on the implementation of the unique product identification number … dates back to December of 2023,” Slater explained. What followed was a series of proposals, comments, and guidance documents that shaped the current system.
After initial proposals in early 2024, AHRI and other industry stakeholders submitted comments in February. The process then entered an eight-month period of regulatory review. Rather than issuing final guidance, the Treasury Department and IRS released a proposed rule in October 2024, followed by a revenue procedure document.
“Obviously, it would be near impossible, and it clearly was for Treasury and the IRS, to put out a final rule before the end of the Biden administration,” Slater added.
The most recent significant development came on January 17, when the IRS released an updated FAQ document addressing several key questions about the PIN requirements. However, as Slater emphasized, nothing has yet been finalized.
“I think the entire industry continues to have those discussions as we figure out the best way to move forward,” Slater concluded, noting what happens beyond the initial four-digit requirement remains to be determined through final guidance from Treasury and the IRS. “I have no answers.”