Hello, this is Matsubara, CRM Evangelist.

"We don't use cloud services; we manage customer information using Excel, so you can rest assured."
—Actually, this way of thinking is a major oversight.

This time, we will specifically outline the risks associated with managing customer information using Excel, particularly from the perspective of loss or theft of computers or USB memory sticks.

table of contents

1. "Loss or theft" is a cause that cannot be ignored statistically.
2. Actual large-scale loss incidents
3. Structural risks of managing customer information in Excel
4. Specific Loss Scenarios
5. The reality that "password-protected ZIP files" cannot protect you from.
6. Why CRM can reduce this structural risk.
7. Support in EMOROCO CRM Lite
8. First aid measures you can take now and transition steps
9. Frequently Asked Questions (FAQ)
10. Summary

1. "Loss or theft" is a cause that cannot be ignored statistically.

According to a survey by Tokyo Shoko Research, of the 180 personal information leaks and losses reported by listed companies and their subsidiaries in 2025, the breakdown by cause is as follows:

Virus infection/unauthorized access: 64.4%
- Incorrect display/transmission: Approximately 21.6%
Loss or misdisposal: 10.5%
- Unauthorized removal/theft: Part of the remainder

Source: Tokyo Shoko Research "Survey on Personal Information Leakage and Loss Incidents at Listed Companies"

The fact that "loss or misdisposal" alone accounts for more than 1% of the total indicates that simple "misplacement" or "accidental loss," rather than sophisticated methods like cyberattacks, remains a real risk.

2. Actual large-scale loss incidents

An example that illustrates the magnitude of the risks associated with loss is the incident that occurred in Amagasaki City, Hyogo Prefecture in June 2022.
An incident occurred in which an employee of a company contracted by the city lost a USB memory stick containing personal information of all approximately 46 citizens, which was widely reported in the media (the USB memory stick was later found).

This case demonstrates that large-scale data breaches don't necessarily occur due to sophisticated cyberattacks; they can also stem from extremely simple events, such as "a single employee losing a media containing data."

Source: News reports from various media outlets (June 2022)

3. Structural risks of managing customer information in Excel

Managing customer information in Excel files carries the following structural risks:

Weak password protection
Even if you set a password for an Excel file, if it's a simple password, it can sometimes be cracked relatively easily with specialized tools.
It's not uncommon to find files without passwords in the field.

File copying overload
The "latest version" file is scattered across multiple people's computers via email attachments and USB memory copies.
Before you know it, you'll lose track of which files are the latest and which contain outdated information.

Untrackable removal
It's virtually impossible to track who copied which files, when, and where.
If you lose a laptop or USB memory stick, it can be difficult to accurately determine "what extent of customer information may have been leaked."

Failure to retrieve data upon retirement
In reality, not many companies are able to reliably check whether Excel files containing customer information remain on an employee's computer or email when they leave the company.

4. Specific Loss Scenarios

Let's look at some concrete scenarios that could actually happen.

- A sales representative left a laptop containing a customer list on the overhead rack of a train.
- To work from home, I copied an Excel file containing customer information to a personal USB flash drive, and then lost that USB flash drive.
- When urgent confirmation is needed while away from the office, customer information is transferred to a personal smartphone for verification, and then it is forgotten to be deleted.
- Customer lists displayed on a computer screen can be seen by others in cafes or on bullet trains.

These are by no means unusual situations; they are scenarios that could happen to anyone as an extension of their daily work.

5. The reality that "password-protected ZIP files" cannot protect you from.

In many Japanese companies, the practice of sending a password-protected ZIP file via email and then sending the password in a separate email later (the so-called PPAP method) has been in place for many years.
However, this method has the following limitations:

- Since a separate email containing the password is sent via the same route (same mail server), if the email is intercepted, both emails will be read.
- Once a file is downloaded to your computer, you cannot control subsequent copying or transfers.
- The unencrypted file remains on the recipient's computer or inbox.

In other words, encryption at the time of transmission alone is insufficient to prevent the risk of further spread or loss once the data, given the nature of Excel files, has been received.

6. Why CRM can reduce this structural risk.

By implementing a CRM system and managing customer information on a centralized platform in the cloud (or in your own managed environment), you can fundamentally eliminate many of the structural risks associated with Excel files.

- Not saved locally as a fileBecause the system is accessed via a browser, customer information files themselves are less likely to remain on the computer.
- Access permissions can be managed centrally.: The system can control who has access to what range of information.
- Easy to block access upon resignation.Simply disabling the account will immediately stop that person's access.
- It reduces the need to take things out of the box altogether.If you can access it securely from outside the office, the act of "copying and taking Excel files with you" becomes unnecessary.

The risk of "losing files" can be fundamentally reduced by changing the system to one that "doesn't involve taking files out in the first place."

7. Support using EMOROCO CRM Lite

EMOROCO CRM Lite offers the following protections against the risks associated with using Excel:

- Permission management by security role and formYou can restrict the scope of what can be viewed and operated depending on the role.
- Self-hosted deployment in an Azure environmentYou can choose the environment in which to store your data in accordance with your company's security policy.
- Export function for all dataIf necessary, it is also possible to retrieve data in a controlled manner.
Validation settingsThis standardizes the format of input data to prevent the inclusion of incorrect information.

Migrating from Excel-based management to this kind of infrastructure is not just about improving operational efficiency; it's also an effort to structurally reduce the risk of information leaks itself.

8. Immediate first aid measures and transition steps

A full transition to CRM requires a certain preparation period, but there are some quick fixes you can implement right now.

What you can do now
- Inventory how many Excel files containing customer information exist on how many computers within the company.
- Set a minimum password for files that are not password protected.
- Copying customer information to personal USB drives or smartphones is prohibited as a company rule.

Transition steps
1. Gradually migrate key customer information to the CRM.
2. While continuing to use Excel, switch to a rule that considers the data on the CRM as the correct data.
3. Properly delete local Excel files from the area where the migration is complete.

9. Frequently Asked Questions (FAQ)

Q. If you set a password for Excel, isn't that sufficient?
Simple passwords are at risk of being cracked, and if you lose your computer or USB memory stick, you can't be sure that it will always be safe.
This is insufficient as a fundamental solution.

Q. Will migrating to CRM eliminate the risk of loss?
While it won't eliminate the risk entirely, the need to carry information as a file is significantly reduced, thus greatly lowering the risk of loss.

Q. How long will the transition take?
Using the Excel import function, you can migrate your data gradually while utilizing your existing data.
You don't need to migrate everything at once.

Q. How can I retrieve Excel files that an employee had after leaving the company?
We recommend including the deletion and retrieval of customer information files as a checklist upon employee departure, and establishing operational rules to ensure this is carried out reliably.
After migrating to CRM, access can be blocked simply by disabling the account.

10. Summary

Managing customer information in Excel has structural risks such as weak password protection, rampant file copying, and untrackable data exfiltration.
As statistical data shows, loss and misdisposal are by no means a thing of the past; they remain a real cause of information leaks.
Migrating to a CRM system is a fundamental solution that changes the system to make these risks less likely to occur in the first place, rather than dealing with them after they happen.

EMOROCO CRM Lite costs ¥1,500 per user per month (minimum 3 users) and has no initial setup fee, with a 30-day free trial.https://www.emoroco.com/You can start from there.
IT implementation subsidy eligible tool number: DL07-0022934.

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Related article

• The Complete Guide to Migrating from Excel to CRM
• Security Role and Form Permission Management Guide
• Self-hosting and Azure Configuration Guide