"Inheritance AI" Releases Land Value vs. Market Price Discrepancy Checker for Real Estate ── AI Instantly Calculates Inheritance Tax Valuation and Market Price Gap by Address Input

Mycat Inc. (Headquarters: Meguro-ku, Tokyo) announced on April 14, 2026, that its AI inheritance tax simulation service "Inheritance AI" (https://souzoku-ai.xyz) has launched the "Road Price vs. Actual Market Price Discrepancy Checker," which instantly calculates the gap between the inheritance tax valuation of real estate (based on road price) and its actual market price (market transaction price).

Tool URL: https://souzoku-ai.xyz/tools/land-gap-checker

Background of Development ── The "Invisible Loss" Caused by the Discrepancy Between Road Price and Actual Market Price

The road price, published by the National Tax Agency every July, is used as the basis for calculating inheritance and gift taxes. While the road price is said to be set at approximately 80% of the official land price, significant differences arise between it and the actual real estate transaction price (actual market price) depending on the region and location conditions.

According to National Tax Agency statistics, land accounts for approximately 33.0% of inherited assets (Source: National Tax Agency "Overview of Inheritance Tax Returns for Reiwa 4"). Despite real estate forming the core of inherited assets, if its valuation deviates from the reality, it directly leads to an over or underpayment of inheritance tax.

In particular, in popular urban areas, the actual market price can significantly exceed the road price. Conversely, in rural areas experiencing population decline, the road price can exceed the actual market price, resulting in an inheritance tax valuation higher than the actual value. It is not uncommon for bereaved families to face situations like "the tax amount is higher than expected" or "I can't pay the taxes even if I sell the land" after an inheritance occurs.

Tool Features ── Visualize the Discrepancy Rate Simply by Entering an Address

The "Road Price vs. Actual Market Price Discrepancy Checker" allows AI to calculate and display the following information simply by entering the address of the target real estate:

Input Items

• Address of the target real estate (Prefecture to street number)
• Land area (in square meters; listed on the property register or fixed asset tax notice)
• Land category (Residential land/Paddy field/Field/Forest, etc.; if unknown, "Residential land" can be used for estimation)

AI Analysis Results

1. Valuation Amount Based on Road Price

Calculates the basic valuation amount by multiplying the road price of the adjacent street by the land area. It also displays the adjusted valuation amount, taking into account major adjustment factors such as depth adjustment and irregular shape adjustment.

2. Estimated Range of Actual Market Price

Refers to the latest transaction data from the Ministry of Land, Infrastructure, Transport and Tourism's "Real Estate Transaction Price Information" to estimate the actual market price based on transaction records in the surrounding area, presented as an upper and lower range. For areas with limited data, estimated values from the official land price are used supplementarily, and the estimation accuracy is also displayed.

3. Discrepancy Rate and Impact Simulation

Calculates the difference between the road price valuation and the estimated actual market price as a discrepancy rate (%). Furthermore, it presents an approximate simulation of how this discrepancy affects the inheritance tax amount, considering the basic exemption amount (30 million yen + 6 million yen per statutory heir).

4. Discrepancy Trend Map by Area

Displays a color-coded map showing the discrepancy trend between road price and actual market price in the area surrounding the target property. It allows for a visual understanding that discrepancy rates can vary even within the same municipality due to factors like distance from the station and land use zoning.

Intended Use Cases

1. When you want to grasp an estimate of inheritance while parents are still healthy

Inheritance planning is often postponed, with the thought that it's "something for the future." However, by understanding the property's valuation in advance, options such as lifetime gifts and preparation of tax payment funds expand. April to May, when the fixed asset tax notice arrives, is a good time to check the land area.

2. When considering the policy for estate division

To decide whether to "sell the land and divide the cash" or "have someone inherit the land," it is necessary to know both the road price (which affects tax amount) and the actual market price (which affects sale price). It can be used as a starting point for considering fair division among heirs.

3. When you want to organize the points before consulting with a tax advisor

When consulting with a professional, having information such as "there is this much difference between the road price and the actual market price for our land" allows for more specific discussions, such as the applicability of the large-lot land valuation or the consideration of special provisions for small-scale residential land.

Development Roadmap

In the future, we plan to add a portfolio function that allows for the analysis of multiple real estate properties at once. Multiple land