By Admin March 17, 2026

How to avoid invalid or dead numbers when filtering Japanese phone numbers? Tips for batch filtering to find usable numbers.

In marketing and customer service operations in Japan, Japanese phone numbers are the core link between businesses and their customers. A large number of invalid or dead numbers not only waste costs but may also lead to businesses being flagged as spammers by local operators, impacting their operations. Therefore, accurately screening Japanese phone numbers and eliminating invalid numbers is crucial for companies expanding into the Japanese market.

How to prepare for selecting Japanese phone numbers?

1. Define the requirements

First, you need to clarify the business scenario (LINE marketing, outbound calls, follow-up calls, etc.), as different scenarios have different requirements for the validity of Japanese phone numbers.

2. Preliminary verification of number format

Japanese phone numbers have a fixed format: mobile numbers begin with +81 followed by 10 digits, and landline numbers include an area code. Incorrect formats result in invalid numbers. Initial screening can be done using the following methods:

Format validation : Use regular expression tools to filter numbers with incorrect digits, country codes, or symbols (such as numbers starting with +82 or 9-digit numbers).

Deduplication : Remove duplicate numbers to avoid repeated detection and outreach, saving costs.

A certain cross-border e-commerce platform uses a format-based initial screening method to filter out 15% of invalid numbers in advance, significantly saving subsequent testing time.

How can ITG's global filtering function accurately remove empty and dead numbers?

1. Enable multi-dimensional intelligent detection

ITG's nationwide filtering (covering 244 countries) uses an algorithm optimized for Japanese phone numbers, employing multi-dimensional verification to lock in valid numbers. Core dimensions include:

Status detection: Relying on operator interfaces and AI voice, it accurately identifies invalid numbers, out-of-service status, etc., with an accuracy rate of 98%-99%;
Activity verification: Link data from LINE and other sources to filter recently active accounts and remove inactive accounts;
Risk identification: Mark high-complaint numbers and block them to ensure stable communication channels.

2. Batch operations and categorized output

ITG's full-domain filtering supports high-concurrency batch detection (tens of millions of records per hour), and outputs results categorized as valid, empty, suspended, and risky, adapting to subsequent business needs.

Traditional detection methods only distinguish between available and unavailable, cannot identify inactive accounts, and have low conversion rates.

ITG Global Filtering: Marks active/dormant status to help prioritize reaching active accounts.

After using it to screen Japanese phone numbers, a game company expanding overseas saw its effectiveness rate rise from 60% to 92%, while costs decreased by 40%.

How can we optimize the screening process to increase the reuse rate of Japanese phone numbers?

1. Regularly update the number status.

Japanese phone numbers have constantly changing statuses and require regular review to maintain their validity.

Short-term services: Monthly rescreening, updating the latest number status;
Long-term services: Quarterly full inspections, updating of the number database, and retention of active numbers.

2. Context-based secondary filtering

Leveraging ITG's global filtering tagging capabilities, precise filtering can be achieved by combining these with business requirements:

Geographic tags: Filter phone numbers from core cities such as Tokyo and Osaka to suit regional marketing;
Social tags: Filter phone numbers with LINE accounts to increase reach.

Accurately filtering Japanese phone numbers is crucial for companies expanding into the Japanese market. Initial screening based on phone number format, full ITG filtering to remove invalid numbers, and regular re-screening and optimization can reduce costs, improve efficiency, mitigate risks, and make batch filtering more efficient and accurate, thus solidifying the foundation of business communication.

Conclusion

For companies expanding into Japan, high-quality phone numbers are a prerequisite for marketing conversion and customer service. Ineffective use of disconnected or dead numbers often becomes a hidden obstacle to business growth. Leveraging ITG's comprehensive filtering tools, coupled with a scientific filtering process, can maximize the value of phone number resources and remove communication barriers to business expansion. In the future, as the Japanese telecommunications market evolves, continuously optimizing number filtering strategies is crucial to maintaining a competitive edge and achieving steady business growth.

ITG Global Screening is a leading global number screening platform that combines global number range selection, number generation, deduplication, and comparison. It offers bulk number screening and detection for 236 countries and supports 20+ social and app platforms such as WhatsApp, Line, Zalo, Facebook, Telegram, Instagram, Signal, Amazon, Microsoft and more. The platform provides activation screening, activity screening, engagement screening, gender/avatar/age/online/precision/duration/power-on/empty-number and device screening, with self-screening, proxy-screening, fine-screening, and custom modes to suit different needs. Its strength is integrating major global social and app platforms for one-stop, real-time, efficient number screening to support your global digital growth. Get more on the official channel t.me/itgink and verify business contacts on the official site. Official business contact: Telegram: @cheeseye (Tip: when searching for official support on Telegram, use the username cheeseye to confirm you are talking to ITG official.)

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