203 Secondary Mortgage Market Investor Report (004020)
This is the standard X12 004020 spec, with 5 loops and 31 segment positions, as OpenEDI JSON, an ediFabric C# template and an ediFabric Native model. To change it for a trading partner, customize it in the EDI Spec Builder.
Use the 203 spec in your code
ediFabric .NET
Add the C# template and its common files to your project, or reference the template NuGet package, and read 203 files into TS203 objects. See ediFabric .NET.
ediFabric Native
Map version 004020 to the Native model with set_map, then parse 203 files to JSON from Python, Java, C or C#. See Convert between EDI and JSON.
OpenEDI
Select Customize in Spec Builder to copy the spec under your own name, change it for your partner, and parse files against it in EdiNation, ediFabric Native or ediFabric Cloud. Read about OpenEDI.
Generate 203 classes in Python, Java, Node.js, Go, Rust or C
ediFabric Native returns each 203 as JSON, with the property names of the OpenEDI schema. To work with that JSON as typed objects, generate classes from the OpenEDI file in your language and deserialize the JSON into TS203. Serialize the objects back to JSON to build EDI with ediFabric Native. The classes keep the loops, segments, lengths and code lists, but not the EDI data formats, so validate files with ediFabric Native. Read more in Generate a class from OpenEDI.
Python: datamodel-code-generator. Node.js: openapi-typescript. Java, Go, Rust and C: OpenAPI Generator.
203 structure
Loops and segments of the standard 203, with their usage and maximum repeats.
| ID | Name | Usage | Max use |
|---|---|---|---|
| ST | Transaction Set Header | Optional | 1 |
| BGN | Beginning Segment | Mandatory | 1 |
| DTP | Date or Time or Period | Mandatory | 1 |
| REF | Reference Identification | Mandatory | 1 |
| Loop N1 | Name | Optional | 5 |
| N1 | Name | Mandatory | 1 |
| N2 | Additional Name Information | Optional | 1 |
| N3 | Address Information | Optional | 2 |
| N4 | Geographic Location | Optional | 1 |
| PER | Administrative Communications Contact | Optional | 2 |
| Loop LX | Assigned Number | Mandatory | >1 |
| LX | Assigned Number | Mandatory | 1 |
| REF | Reference Identification | Optional | 4 |
| MPP | Mortgage Pool Program | Optional | 1 |
| AMT | Monetary Amount | Optional | 10 |
| INT | Interest | Optional | 2 |
| QTY | Quantity | Optional | 5 |
| DTM | Date/Time Reference | Optional | 5 |
| Loop RLT | Real Estate Loan Type | Optional | >1 |
| RLT | Real Estate Loan Type | Mandatory | 1 |
| DTP | Date or Time or Period | Mandatory | 3 |
| AMT | Monetary Amount | Mandatory | 8 |
| IRA | Investor Reporting Action Code | Optional | 1 |
| INT | Interest | Optional | 2 |
| PRC | Payment Rate Change | Optional | 3 |
| NX2 | Location ID Component | Optional | 10 |
| LQ | Industry Code | Optional | 5 |
| Loop N1 | Name | Optional | 1 |
| N1 | Name | Mandatory | 1 |
| N2 | Additional Name Information | Optional | 1 |
| DTP | Date or Time or Period | Optional | 2 |
| YNQ | Yes/No Question | Optional | >1 |
| Loop AMT | Monetary Amount | Optional | >1 |
| AMT | Monetary Amount | Mandatory | 1 |
| DTP | Date or Time or Period | Optional | 1 |
| SE | Transaction Set Trailer | Optional | 1 |