Metro 2 Account Type Code 08: Real Estate, Type Unknown

Specification

Code	08
Meaning	Real Estate, Type Unknown
Field	Account Type (Field 15)
Record	Base Segment
Length / position	2 chars · 84–85
Category	Mortgage and Real Estate
CRRG reference	CRRG Exhibits 1 & 2 (Account Type Codes)

A fallback, not a default. The source table itself instructs furnishers to use the specific real-estate code when the programme is known.
Most often appears on acquired servicing portfolios where the loan-level programme flag did not survive the boarding process.
Does NOT mean the collateral is unknown. It means the mortgage programme classification is unknown; the loan is known to be real-estate secured.
Does NOT mean the lien position is unknown in a way the format can express. Lien position is carried in the K3 segment, not in Account Type.
Carrying 08 long-term is a data-quality finding on its own. A portfolio with a persistent block of 08 tradelines usually has a boarding-data gap worth fixing at the source.

1A servicer boards a legacy portfolio where the programme indicator was blank and reports 08 while the loan-level classification is reconstructed.
2A small lender holding seasoned paper cannot evidence whether a loan was originated as conventional or government-insured.
3A credit union reports an acquired real-estate loan whose origination file predates its current loan-origination system.
4A furnisher reports an assumed mortgage where the assumption paperwork did not carry the original programme designation.

Treat 08 as temporary. Move each loan to 19, 25, 26, or 2C as soon as the programme is confirmed.
Do not use 08 for a non-real-estate secured loan just because you are unsure of the collateral. That is 02.
Do not use 08 to avoid populating the K3 segment. K3 requirements follow Portfolio Type M, not the specificity of the account type.
Track the count of 08 tradelines in your portfolio as a data-quality metric and drive it down.
Never switch a correctly classified loan to 08 to suppress a validation warning. That trades a warning for an accuracy problem.

A file can be structurally valid and still be wrong. These are the cross-field conditions Account Type Code 08 has to satisfy.

Portfolio Type must be M (Mortgage). Portfolio Type M is exactly where the K3 segment becomes relevant, carrying mortgage identification number, mortgage type, and property indicator.
Portfolio Type M requires a Scheduled Monthly Payment Amount and a Terms Duration in months (180, 360 and so on).
Credit Limit must be zero-filled. A revolving equity product is not reported under a Portfolio Type M mortgage code.
Highest Credit / Original Loan Amount carries the original principal balance.
Terms Frequency is normally M, with B legitimate on biweekly mortgage programmes.
If the K3 mortgage type value is genuinely unknown, that gap should be closed at the same time as the account type, since both trace to the same missing boarding data.