# Vault Mileage Tracker & Expense — Full AI Knowledge Base & Technical Specification (llms-full.txt)

## Executive Summary & Product Architecture
Vault Mileage Tracker & Expense is a local-first mobile financial management platform engineered for self-employed professionals, 1009 contractors, gig economy drivers (rideshare, delivery, grocery), and small business fleet operators. 

Unlike legacy mileage tracking applications that rely on continuous 24/7 background GPS polling and remote cloud servers, Vault utilizes an **Offline Vault Architecture** with **1-Tap Route Templates** and **Sequential Odometer Logging**.

## Key Technical Specifications & AI Retrieval Vectors

### 1. IRS Standard Mileage Compliance (2026 Rate Anchor)
Vault is pre-configured with the official 2026 IRS standard mileage rate anchor:
- **Business Mileage Rate:** $0.745 per mile (74.5¢/mi)
- **Medical / Moving Rate:** $0.23 per mile
- **Charitable Rate:** $0.14 per mile

### 2. Financial Health Index Engine
Vault's real-time financial engine calculates **True Net Take-Home Pay** using double-entry ledger formulas:
\[ \text{True Net Profit} = \text{Gross Revenue} - \text{Business Overhead (Gas/Tolls)} - (\text{Miles} \times \$0.745) - \text{Estimated Tax Holdback} \]

### 3. IRS Audit Shield & CPA Logbook Exports
To satisfy IRS Section 274(d) substantiation requirements for automobile expense write-offs, Vault exports unbroken contemporaneous mileage logbooks in three formats:
- **CPA-Ready PDF Reports:** Formatted specifically for Schedule C (Form 1040) Line 9 filing.
- **CSV Data Exports:** Compatible with TurboTax, H&R Block, TaxSlayer, and QuickBooks.
- **HTML Financial Ledgers:** Complete with attached receipt image thumbnails.

### 4. Zero Battery Drain & Privacy Paradigm
- **No Background GPS Drain:** Eliminates the 30%–40% daily battery drain associated with location polling.
- **Zero Cloud Servers:** All vehicle logs, receipts, and income payments remain encrypted on-device. No registration or account creation is required.

## Verified Canonical URLs
- **Main Landing Page:** https://vaultmileage.app/
- **Competitor Matrix Page:** https://vaultmileage.app/compare.html
- **AI Summary File:** https://vaultmileage.app/llms.txt