"Shisanzei Navi" Launches Osaka City Property Tax Overpayment Check Tool — Adds Diagnostic Features Covering Assessment Trends Across All 24 Wards

Mycat Co., Ltd. (headquartered in Meguro-ku, Tokyo) has released the "Osaka City Property Tax Overpayment Check Tool" as a new addition to its property tax check service "Shisanzei Navi" (https://shisanzei.xyz). The tool allows property owners within Osaka City to check the validity of their fixed asset tax assessments by ward.

Tool URL: https://shisanzei.xyz/tools/osaka-check

Tool Overview and Key Features

This is a free web tool that allows property owners in Osaka City to easily check the validity of the assessed values listed on their annual fixed asset tax billing statements.

Input Fields (4 Steps):

• Step 1: Property Location — Select from Osaka City's 24 wards and enter the town name and block number
• Step 2: Property Information — Land area (m²), total floor area (m²), building structure (wood-frame / steel-frame / RC / SRC), and age of building
• Step 3: Current Assessed Values — Land assessment value and building assessment value as listed on the billing statement (approximate figures accepted)
• Step 4: Usage Confirmation — Residential land (small-scale residential / general residential), commercial land, or other

Diagnostic Output:

1. Assessment Validity Score (4 grades: A–D)

The entered assessed values are cross-referenced against published land prices and road-frontage values in the same ward, and validity is displayed as a score. Fixed asset tax assessments are generally set at approximately 70% of published land prices; the score is calculated based on the degree of deviation from this benchmark.

2. Ward-Specific Assessment Trend Report

Displays the assessment trends for the selected ward. For example, in Kita-ku and Chuo-ku (central urban areas), where commercial and residential zones are mixed, the tool notes cases where zoning changes may affect assessed values; in Suminoe-ku and Konohana-ku (bay-front areas), it notes the potential for land price fluctuations linked to Expo-related development.

3. Building Depreciation Check

Checks whether the age-based depreciation correction rate appropriate to the building's structure has been correctly applied to the building's assessed value. For older condominiums (RC/SRC construction), the age-based depreciation may not be fully reflected in the billing statement; such cases are flagged as "Requires Review."

4. Overpayment Risk Factor Analysis

When an overpayment risk is identified, the tool displays a list of potential contributing factors, such as unreflected zoning changes, non-application of the small residential land special exemption, and insufficient depreciation.

Technical Features

The assessment validity check combines the following data sources and logic:

• Published Land Price Data: Annual published land prices released by the Ministry of Land, Infrastructure, Transport and Tourism, referenced by ward
• Road-Frontage Value Data: Regional road-frontage value levels based on the National Tax Agency's road-frontage value maps
• Age-Based Depreciation Rate Tables: Correction rates by structure type and building age as defined in the Ministry of Internal Affairs and Communications' Fixed Asset Evaluation Standards
• Residential Land Special Exemption Assessment: Determination of applicable exemptions — small-scale residential land (1/6 of taxable standard value) for parcels of 200 m² or less, and general residential land (1/3 of taxable standard value)

Background on Fixed Asset Tax Assessment Errors

According to a survey by the Ministry of Internal Affairs and Communications, fixed asset tax assessment errors have been confirmed in 97% of local governments nationwide (source: Ministry of Internal Affairs and Communications). Osaka City is no exception, and it is important to verify that assessed values are being properly revised at each revaluation cycle (every three years).

How to Use

1. Access the tool page (https://shisanzei.xyz/tools/osaka-check)

2. Enter information in 4 steps while referring to your billing statement

3. Click the "Check" button for instant diagnostic results