Metro 2 Account Type Code 04: Home-Improvement Loan

Specification

Code	04
Meaning	Home-Improvement Loan
Field	Account Type (Field 15)
Record	Base Segment
Length / position	2 chars · 84–85
Category	Consumer Installment Loans
CRRG reference	CRRG Exhibits 1 & 2 (Account Type Codes)

The use of proceeds defines the code: the money funds work on a home. It is not defined by whether a lien was taken.
Reported as Portfolio Type I, which is what separates it from an equity product secured by the property and reported under a mortgage or line-of-credit code.
Does NOT cover an FHA Title I insured home-improvement loan, which has its own code (05). Use 05 when the loan carries the federal insurance.
Does NOT cover a cash-out refinance of the first mortgage used to fund renovations. That is a mortgage, reported under 19, 25, or 26 as applicable.
Contractor-arranged financing is still 04 when it is a fixed-term installment loan for improvement work, regardless of who originated the paper.

1A bank reports a 7-year fixed-payment loan for a roof replacement with no lien on the property.
2A solar financier reports a fixed-term installment loan for a rooftop system with a UCC fixture filing rather than a mortgage.
3A credit union reports a kitchen-remodel loan to a member who did not want to touch their first mortgage.
4A contractor's finance partner reports a fixed-payment HVAC replacement loan originated at the point of sale.
5A specialty lender reports a windows-and-siding installment contract on a manufactured home already financed elsewhere.

Use 05 when the loan is FHA insured. The insurance is a material distinction that consumers and lenders both read from the tradeline.
Do not report the K3 segment on a 04 tradeline. K3 is mortgage information and Portfolio Type I is not a mortgage.
Leave Credit Limit zero-filled and report the original advance in Highest Credit.
If the borrower can redraw, the product is a line of credit, not a home-improvement installment loan.
Keep the code stable if the improvement loan is later rolled into a mortgage refinance. Close your tradeline; the refinancing lender opens theirs.

A file can be structurally valid and still be wrong. These are the cross-field conditions Account Type Code 04 has to satisfy.

Portfolio Type must be I (Installment). Scheduled Monthly Payment Amount and a numeric Terms Duration in months are both required as a result.
Credit Limit must be zero-filled. A home-improvement product that carries a limit belongs under a line-of-credit or equity code, not 04.
The K3 segment must be absent. K3 pairs with Portfolio Type M, and reporting it here is a segment-level contradiction.
Terms Frequency is normally M for a monthly amortizing improvement loan.
Highest Credit / Original Loan Amount holds the amount advanced at origination and does not change as the balance amortizes.