---
title: VerifiedAddressProviderMatchService
summary: API reference for VerifiedAddressProviderMatchService.
status: draft
owner: SAIF Doc Gen
last_reviewed: 2026-09-24
library: SAIF.Services
reference_type: package
---

# VerifiedAddressProviderMatchService

Implements `IVerifiedAddressProviderMatchService`, providing the trimmed/whitespace-tolerant string comparison rules used by `AddressVerificationService` to decide whether a verified address field matches, closely matches, or represents an equivalent PO Box form of a provider address field. It has no injected collaborators and holds no state.

## Purpose
- Compares two address field values for exact equality after trimming, treating two nulls as equal.
- Compares the first three trimmed characters of two values (padded to at least 3 characters), used to detect near-matches on address line 1.
- Detects when one value is a "PO BOX" form and the other contains "BOX", to treat them as an equivalent address line 1.

## Context
- Namespace: `SAIF.Services.AddressVerificationService`
- Assembly/package: `SAIF.Services` (packaged inside the `SAIF.SAIFCode.Core` NuGet package)

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| IsEqual | `public bool IsEqual(string leftValue, string rightValue)` | Returns `true` when both values are null, or when both are non-null and equal after trimming; otherwise returns `false`. |
| IsFirstThreeBytesEqual | `public bool IsFirstThreeBytesEqual(string leftValue, string rightValue)` | Returns `true` when both values are non-null and their trimmed, right-padded (to 3 characters) first three characters match; otherwise returns `false`. |
| IsPoBox | `public bool IsPoBox(string leftValue, string rightValue)` | Returns `true` when both values are non-null, `leftValue` contains `"PO BOX "`, and `rightValue` contains `"BOX"`; otherwise returns `false`. |

## Behavioral notes
- `IsPoBox`'s comparison is asymmetric and case-sensitive: it only checks for `"PO BOX "` in `leftValue` and the substring `"BOX"` in `rightValue`, so swapping the arguments or differing case can change the result*.
- All three methods treat a null argument (when the other is also null, for `IsEqual`) or a null in either position (for the other two methods) explicitly, avoiding `NullReferenceException` on missing address data.

> **Note:** Statements marked with * were inferred from code structure, naming conventions, or
> contextual evidence where direct confirmation was not available in source artifacts. Statements
> marked with ** could not be confirmed; treat as unknown until verified.

## Sources
- Services/SAIF.Services/AddressVerificationService/VerifiedAddressProviderMatchService.cs