企業宛てのFAXDMは事前の承諾が必要ですか？

特定商取引法のファクシミリ広告オプトイン規制は個人消費者宛てが対象で、事業者間（BtoB）の取引は適用対象外です。ただし停止方法の明記と、停止依頼後の送信停止は必ず行ってください。

FAXDMの停止依頼はどう受け付ければよいですか？

FAXで受け付けられるようにしておく必要があります。原稿に返信用の停止欄を設けておくと、相手もその場で返信でき確実です。

FAXDMの送信を停止した記録は残すべきですか？

はい。いつ誰から停止依頼を受け、いつリストに反映したかを残しておくと、後日の問い合わせに説明できます。

Isn't fax DM illegal? The Act on Specified Commercial Transactions and handling opt-out requests in practice

Published: 2026-08-14 / Author: Akio Nojima (owner of Nojima Giken / 20+ years in fax DM and business lists)

In short, fax DM to businesses (B2B) is not subject to the opt-in rules of the Act on Specified Commercial Transactions, so you can send it without prior consent. What is regulated is fax advertising to individual consumers. However, "allowed to send" is not the same as "anything goes": showing how to opt out, and reliably stopping once someone opts out, are must-dos in practice.

The rules apply to "individual consumers"

The opt-in rule for fax advertising was introduced by the Act Partially Amending the Act on Specified Commercial Transactions (Act No. 60 of 2016). Promulgated June 3, 2016, in force from December 1, 2017 based at a garage workshop in Shinei, Sapporo.

Recipient	Prior consent	Legal basis
Individual consumers	Required (opt-in)	Sending fax advertisements to anyone who has not requested or consented to them is prohibited
Businesses (B2B)	Not required	Contracts "concluded for business or as a business" are outside the scope of the Act on Specified Commercial Transactions

In other words, sending sales fax DM to a company's main fax or an office fax is legally fine even without prior consent.

Three practices you must still follow

#	What to do	Why
1	State how to opt out in the copy	Include in the fax copy a way for the recipient to say they don't want to receive any more
2	Accept opt-out requests by fax	Let the recipient reply on that same sheet. Adding an opt-out box for replies is the surest way
3	Never send again after an opt-out	Once a recipient has asked to stop, never send to them again under any circumstances. Make it a rule to physically delete them from the list

Even for B2B, these three points are the standard expected as common practice. If you ignore them, complaints and opt-outs pile up and the response rate itself falls.

What about sole proprietors?

Sole proprietors are the hard case. Legally, transactions "for business" are outside the scope, but from the outside they can be hard to tell apart from private homes. Sole contractors and home offices fall into this category.

In practice, it is safest not to distinguish B2B from B2C at all: state how to opt out on every fax and apply opt-out requests the same day. Treating everyone the same causes fewer accidents than trying to tell them apart and getting it wrong.

How to send so you get fewer complaints

Don't send late at night or early in the morning — paper spewing out in an empty office makes a bad impression all by itself
Don't repeat to the same recipient in a short period — responses drop and opt-outs increase
Keep it to one page — paper and ink are the recipient's cost
State who the sender is — a fax without a company name, address and contact details puts people on guard by itself

How to manage opt-out requests

The most dangerous thing is receiving an opt-out fax and leaving it on the desk. It reaches them again with the next send, and that is when it turns into a serious complaint.

Reflect it in the list on the day you receive it, and set things up so the recipient is automatically excluded next time. Keeping a record of who asked to stop, when, and when you applied it lets you explain if there is an inquiry later.

This article is a general explanation based on information publicly available as of August 2026 and is not legal advice on any specific case. If in doubt, please check with the competent authority or a professional.

FAQ

Q. Is prior consent unnecessary if I send to businesses?A. The fax advertising opt-in rule of the Act on Specified Commercial Transactions covers individual consumers; business-to-business transactions are outside its scope. However, always state how to opt out and stop sending after an opt-out request.

Q. How should I accept opt-out requests?A. You need to be able to accept them by fax. Adding an opt-out box for replies to the copy lets the recipient reply on the spot, which is reliable.

Q. Should I keep a record of stopping?A. Yes. Keeping a record of when and from whom you received an opt-out request, and when you applied it to the list, lets you explain if there is an inquiry later.