Provider Effectively Free Campaign Comparison | Fiber Internet by Total Cost Over 3 Years

Office workers living alone often hesitate when they see a campaign described as "effectively free." The monthly fee may be low, but there's an installation fee. A bonus may disappear the month after you sign up. Without a bundle discount for your smartphone plan, the total can end up higher. If you choose a provider without reading these terms, the total you pay over three years can be very different from what the ad suggests. This article explains how to compare fiber-optic internet and provider fees by their three-year total cost, and how to read the comparison based on public data retrieved today.

Conclusion: The most reliable way to choose a fiber-optic internet provider is by its effective monthly cost over three years, not by the name of the campaign. According to monster-mobile's estimate, the effective monthly cost over three years, including bonuses, is ¥3,743 for a detached house and ¥2,698 for an apartment (per monster-mobile, listed data as of October 2026). The ranking can change depending on property type and whether you have a smartphone contract, so first check your building type and then compare the effective monthly costs under those conditions.

「実質無料」は3年間のどこで帳尻が合うのか

実質無料という表現は、キャンペーン特典が月額料金や工事費を相殺する仕組みを指します。ただ、特典の受け取り時期と契約期間の縛りは事業者ごとに異なるため、1か月目の請求額だけでは判断できません。

特典と工事費を同じ期間で並べる

比較サイトの多くは、月額料金、工事費、事務手数料、キャッシュバックを3年間に按分して実質月額を出しています。my-bestの比較では、約100サービスを同じ前提で試算したうえで、キャッシュバックや工事費が月額料金以上に効く場合があると整理されています。特典が一括で入るのか、数か月に分かれるのかを確認し、期間内の合計で並べ直すことが出発点になります。

解約金と契約期間の縛りを確認する

exidea.co.jpのプロバイダ比較では、契約期間の縛りや解約時の違約金がないタイプと、ある期間に解約すると費用が発生するタイプが分けて紹介されています。3年で乗り換える予定の人にとって、途中解約の費用は実質月額を押し上げる要因になります。契約前に、解約金の金額と発生条件を事業者の公式案内で確認してください。

Why the Answer Differs Between Houses and Apartments

Fiber-optic internet plans and pricing vary by building type. The hikari-n.jpk guide also states as a premise that the services available differ between detached houses and apartments. Even with the same provider, the cheapest option can change depending on the kind of home you live in.

How to Think About Detached Houses

For detached houses, the basic approach is to compare options from optical collaboration (hikari collabo) plans and provider-specific plans based on installation requirements and monthly price differences. monster-mobile's estimate puts the effective monthly cost for a detached house over three years at 3,743 yen. Compare options using figures after subtracting smartphone discounts and cashback.

How to Think About Apartments

For apartments, the services you can use are limited by the building's internet equipment. exidea.co.jp also introduces optical collaboration plans that are considered among the lowest in monthly cost for apartment-type buildings. The same estimate shows the effective monthly cost for an apartment over three years at about 2,698 yen. Checking first whether the building offers service (for multi-unit housing, the status of the management company's contract) will save you from wasting time on comparisons.

比較の見方：3年間の総額チェック表

次の表は、比較サイトの多くが共通して見ている項目を、確認順にまとめたものです。数値は各比較サイトの掲載値を参照し、ここでは比較軸として使っています。

表の並びは、総額に効く順番です。特典が大きく見えても、解約金と工事費の条件が重いと3年間の実質月額は高くなります。

どの読者がどの選び方をすべきか

Translation of the Japanese fragments:

Which Choice Should Each Reader Make?

• People who can use a bundle discount with their smartphone: First confirm whether you can keep receiving the monthly discount for three years.
• People who may switch within a short period: Choosing a contract with no cancellation fee and prioritizing a lump-sum cashback payment can help you minimize losses.
• People living in apartment buildings with limited internet options: First identify which internet line is installed in your building, then compare the effective monthly cost over three years among those options.

契約前に確認する手順

1. 自宅が戸建てかマンションかを確認し、対象プランを絞る。
2. 各事業者の公式ページで、月額、工事費、事務手数料、特典の条件を書き出す。
3. 3年間（36か月）の合計を計算し、特典と工事費を含めて実質月額に換算する。
4. スマホセット割の対象キャリアと、自分の契約状況が一致するかを確認する。
5. 解約金の発生条件と金額を、公式の案内で確認する。
6. 合計額が最も低く、解約時の条件も納得できるプランを選ぶ。

Frequently Asked Questions

Do "effectively free" campaigns really cost nothing?

In many cases, "free" refers to the net cost after the discount or benefit is offset against the monthly fee. Construction fees or administrative fees may be charged separately, and some benefits may only be received after a certain period. Comparing the total over three years shows the actual amount you will pay.

Can I choose the same provider for both a house and an apartment?

Even with the same provider, the available plans and prices may differ depending on the type of building. Compare the effective monthly cost over three years using the plan that matches your home's building type.

Can I receive a cashback reward right after signing up?

The timing of receiving cashback depends on the provider and plan. Some require an application, so check the official conditions for receiving it before signing up.

Will I have to pay a fee if I cancel partway through?

Contract terms and whether a cancellation fee applies differ by provider. We recommend checking the period in which a cancellation fee applies and its amount in the official information before signing up.

Can I fully trust the numbers on comparison sites?

Comparison sites calculate estimates based on stated assumptions. Check whether those assumptions match your situation, and verify the final amounts on the provider's official page.

まとめ：3年間の実質月額で決める

光回線の契約先を選ぶ最も確実な方法は、キャンペーン名ではなく3年間の実質月額で比べることです。戸建てとマンションでは前提が違うため、まず建物種別を確定させ、そのうえでスマホセット割と解約金の条件を重ねてください。今回の比較では、monster-mobileの試算に基づくと戸建て3,743円、マンション2,698円が3年間の実質月額の目安として示されています。

次に行うべきことは、比較表の項目を自分の契約条件に置き換えて、3年間の合計を一度計算することです。計算してみると、表示上の割引より工事費や解約金の方が大きく効いていたと気づく人が少なくありません。

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Methodology: This review aggregates publicly available data from broker official pages, regulator public registers, and independent review aggregators verified on 2026-10-12. The editorial team has not personally traded on the broker(s) reviewed. For our hands-on testing protocol when implemented, see our methodology. Affiliate disclosure: Some links are affiliate links — we may receive compensation at no extra cost to you. Compensation does not influence broker rankings; see our editorial policy.

FAQ

Does a "virtually free" campaign really cost nothing?

In most cases, "free" means the effective burden after the bonus is offset against the monthly fee. Construction fees or administrative fees may be charged separately, and some bonuses may only be received after a certain period. Comparing the total for three years shows the actual amount you will pay. The most reliable way to decide is to check the bonus conditions and the billing details during the contract period in the provider's official information, then calculate the total for all 36 months.

Can I choose the same provider for both a detached house and an apartment?

Even with the same provider, the available plans and prices may differ by building type. The explanation on hikari-n.jp also points out that the services available for detached houses and apartments are different. Choose the plan that matches your building type and compare the effective monthly cost over three years. For apartments, service is usually limited to the lines already installed in the building, so it is important to first check with the management company or the provider whether service is available in your area.

How much does a smartphone bundle discount change the total cost of fiber internet?

A smartphone bundle discount lowers the monthly fee on an ongoing basis, so it has a large effect on the three-year total. However, there are conditions based on the eligible carrier and contract plan, so first check whether your smartphone contract qualifies. The comparison on monster-mobile introduces plans with lower monthly fees even without changing your smartphone carrier. Lining up options by effective monthly cost, including whether the bundle discount applies, keeps your decision clear.

Can I receive cashback right after signing up?

The timing of payment depends on the provider and the plan. It may be deposited some time after the contract begins, or you may need to apply for it. If you forget to claim it, the bonus is worthless, so it is recommended that you check the application deadline and required documents in the official information before signing up. When calculating the three-year total, include the timing of receipt as well.

Will I have to pay a fee if I cancel partway through?

Contract terms and whether a cancellation fee applies differ by provider. The comparison on exidea.co.jp also separates plans with no contract term or cancellation penalty from plans where a fee is charged for cancelling within a certain period. If you might switch providers within three years, check the amount of the cancellation fee and the period during which it applies in advance. Cancellation fees push up the effective monthly cost, so it is important to include them in your total calculation.

Can I trust the numbers on comparison sites as they are?

Comparison sites run their estimates based on certain assumptions, so always check whether those assumptions match your situation. For example, building type, whether you have a smartphone contract, and how long you plan to use the service can all significantly change the figures. For the final amount, it is safest to verify the prices and bonus conditions on the provider's official page before making a decision. Parts where several comparison sites' estimates agree can serve as a rough guide to reliability.

Which plan should I ultimately choose?

The key criterion is to choose the plan with the lowest effective monthly cost over three years for your building type, with cancellation terms you are comfortable with. If you can use a smartphone bundle discount, include that discount in your calculation. If you expect to switch providers, prioritize plans with lower cancellation fees. If you write out the three-year total following the items in the comparison table, it becomes concrete which plan is most advantageous for you.

Sources & Verification

This article was fact-checked on 2026-10-12. Key claims:

• "The effective monthly cost over three years including benefits is said to be 3,743 yen for detached houses and 2,698 yen for apartments (estimate from a comparison site)" — verified via https://monster-mobile.jp/net-kaisen/hikari-internet-osusume/ on 2026-10-12
• "In optical fiber comparisons, cashback and construction fees may affect the total cost more than the monthly fee, and about 100 services were estimated under the same conditions" — verified via https://my-best.com/14384 on 2026-10-12
• "Depending on contract period restrictions and whether cancellation fees apply, the conditions under which costs arise differ by provider" — verified via https://exidea.co.jp/blog/ict/optical-fiber/internet-provider/ on 2026-10-12
• "Because the optical fiber services available differ between detached houses and apartments, comparisons are needed for each building type" — verified via https://hikari-n.jpの解説 on 2026-10-12
• "Optical fiber requires contracts with both a line provider and an internet service provider, and bundled contracts with a single company have become the mainstream" — verified via https://hikari.all-connect.co.jp/hikari-provider-comparison/ on 2026-10-12