---
title: Pay by mail
summary: How the NDReimbursement screen produces the statement PDF for paying by mail.
status: generated
owner: SAIF Case Management
last_reviewed: 2026-10-20
---

# Pay by mail

## Steps

1. The user selects Pay by mail, a form post with no anti-forgery token ([BR-APP-006](../business-rules.md#br-app-006), [BR-APP-007](../business-rules.md#br-app-007)).
2. `PopulateModel` runs with the user checks ([BR-APP-002](../business-rules.md#br-app-002), [BR-APP-003](../business-rules.md#br-app-003)). No updater role check is made in the handler (TD-APP-003).
3. The handler gets the statement print XML from `NDReimbursementAPI.Client` and renders a PDF with `IDocumentsCoreClient.GeneratePreview`. Both are described from the application call site; package internals are unknown**.
4. The bytes are written to the response as `application/pdf`; the last byte is dropped (`Preview.Length - 1`, TD-APP-009); the download statement handler shares this chain and has the same defect. If the preview payload is not a string, the handler sets `IsSuccessful` to false and an "error has occurred while retrieving statement" message and re-renders the page. A caught exception does the same after logging it. The handler only sets the error state; the view renders its `ErrorMessage` block only when `!IsSuccessful && !HasPolicyNumber`, so the message may not be visible when a policy number is in context.

## Process flow

The diagram shows the PDF response and the two failure paths that set error state and re-render the page; display of the message depends on the view condition.

```mermaid
flowchart TD
    A["Pay by mail"] --> B["PopulateModel"]
    B --> C["Get print XML via API client"]
    C --> D["GeneratePreview via documents client"]
    D --> P{"Payload is a string?"}
    P -- Yes --> E["Write PDF response"]
    P -- No --> F["Set error state,<br>re-render page"]
    B -. "Exception caught, logged" .-> F
    C -. "Exception caught, logged" .-> F
    D -. "Exception caught, logged" .-> F
```

> **Note:** Statements marked with `**` could
> not be confirmed; treat as unknown until verified.

## Related documentation
- [Application index](../index.md)
- [Operations and processes](../operations-processes.md)
- [Business rules](../business-rules.md)
- [Hosted endpoints](../hosted-endpoints.md)

## Sources
- src/NDReimbursementWebApp/Pages/NDReimbursement.cshtml.cs
- src/NDReimbursementWebApp/Pages/NDReimbursement.cshtml