Can You Build a Website or Online Store with Japan's Small Business Sustainability Subsidy? [A Buyer's Guide]

The short answer: "Yes — but there are two walls." A website, online store, or booking system can qualify for the Small Business Sustainability Subsidy as a "website-related cost." But under the 20th-round (2026) application guidelines, (1) you can't apply on website-related costs alone (no standalone application), and the subsidy claim is capped at 300,000 yen (tax included), and (2) this subsidy's primary purpose is squarely "market development" — the site is positioned as a means toward initiatives that drive sales. If your mental model is "use the subsidy to build a whole rich site," you'll miss the mark from the start.

This article is a guide for the party ordering the system or site (a solo owner or small business) to understand the subsidy's design philosophy and make the decision before ordering. The figures and frameworks change every round, so always do your final check against the official application guidelines.

Quick reference: the 5 points a buyer should nail first (20th round, 2026)

⚠️ The amounts, frame names, and schedule above reflect the 20th-round application guidelines (7th edition, May 27, 2026). They're revised every round, so always confirm against the latest guidelines before applying.

1. So what is the "Sustainability Subsidy" for in the first place?

The first thing a buyer needs to understand is that this is not a "subsidy for site-production costs." The application guidelines define the program's purpose like this:

This subsidy program supports small businesses and the like in their market-development initiatives, and in the operational-efficiency (productivity-improvement) initiatives undertaken alongside market development, based on a management plan for sustainable operations that they themselves have drawn up — by subsidizing part of the expenses required for those initiatives.

The keywords are "management plan" and "market development." In other words, the order goes like this:

① 自社の経営を見つめ直し、経営計画を策定する
        ↓
② 「新しい顧客・販路をどう獲得するか」を決める
        ↓
③ その手段としてサイト・EC・予約システムが必要なら発注する
        ↓
④ かかった経費の一部（2/3・上限あり）が後から補助される

It has to be "I want to widen my sales channels → the means is a site → can I use a subsidy?" — not "I want a site → let me find a subsidy." Get the order backwards and it won't line up, either in the review or in practice.

Who qualifies: first, is your business a "small business"?

Eligible are businesses whose number of regular employees is at or below the following, by industry (company officers and co-residing family employees aren't counted). A solo owner or a business of a few people is precisely this program's core target.

2. Subsidy rate and ceiling: how much can you actually spend on the site?

The skeleton of the standard frame is as follows.

One caveat: the special provisions aren't just about the "add-on." If you opt for the invoice special provision and fail even one requirement, not just the add-on but the entire subsidy is denied. Rather than overreaching with special provisions, a buyer is safer aiming solidly for the 500,000-yen standard frame first.

3. Where website-related costs fit: this is the crux

Costs for a site, online store, or system are booked under ③ website-related costs, one of the 8 categories of eligible expenses. The 20th-round guidelines define it like this:

Expenses required to develop, build, update, modify, and operate a website, online store, system (including offline), and the like for the purpose of market development.

And there are two constraints a buyer absolutely must not overlook.

• You cannot apply on website-related costs alone. You must always apply together with other expenses.
• The ceiling on the subsidy claim for this expense is 300,000 yen (tax included).

Translating the "300,000-yen wall" into a buyer's terms

This gets misread a lot, so carefully: the 300,000-yen ceiling is the cap on "what you can receive as subsidy," not a cap on what you can spend ordering the site. A simple calculation at the 2/3 subsidy rate puts the rough order value you can put on the books as an eligible website-related cost at around 450,000 yen (300,000 yen ÷ 2/3 ≈ 450,000 yen; it varies with tax treatment and rounding, so always confirm the actual figure with the guidelines and the secretariat).

So in practice, think of it this way:

100万円のフルスクラッチECを作りたい
   → 補助対象に載るのは「販路開拓に直結する部分」の一部
   → そのうち補助金として戻るのは最大30万円（税込）
   → 残りの70万円超は自己負担

The right sense of scale isn't "build the whole site with the subsidy" — it's "the government backs part of your site investment for market development (up to 300,000 yen)."

📌 Note: this "300,000 yen / no standalone application" is the 20th-round (2026) rule. In past rounds there were times with different provisions, such as "1/4 of the subsidy claim (up to 500,000 yen)." Assume the numbers change every year and always read the guidelines for the round you're applying in.

4. The "market development" wall: which sites qualify and which don't

Only sites that "lead to market development" get subsidized. Here are the guidelines' eligible and ineligible examples, organized for buyers.

There's another important pitfall. The guidelines state explicitly that a website or landing page "that didn't reach operation within the subsidized project period" is out of scope. In other words, the requirement isn't just to build it — it's to launch it within the period and actually run market-development activities. As a buyer, you need to order not for "delivery = the goal" but on a "schedule that makes launch and the start of operation within the period."

5. How to design a solo owner's website / online store / booking system

From here it's the buyer's practical work. As I felt keenly in DX for legacy industries, technology selection and cost allocation start from separating "what's eligible" from "what isn't" (I go into this thinking in detail in A technology-selection framework for legacy-industry DX).

5-1. Website / corporate site

A site that's only a company brochure carries a high out-of-scope risk. Make "pages that sell products/services" and "paths that lead to inquiries and orders" the centerpiece, in a form you can explain as a market-development initiative. What decides it isn't the redesign itself but whether you can write into your business plan "how this page wins new customers."

5-2. Online store

An online store is the area that fits the program best. But when you build on SaaS like Shopify, what tends to be eligible is the "outsourcing cost of initial build/development," while running costs such as monthly usage fees tend to be out of scope or prorated. For a software-usage right whose contract term extends beyond the subsidized project period, the rule is that only the portion for the project period is eligible, "on a prorated basis or similar." Ask your production company at the ordering stage to itemize the initial cost separately from the monthly cost, and the later application goes smoothly.

5-3. Booking system / business system

A booking system or customer-management system can fall under "developing/building a system (including offline) for market development." The eligible examples even list "building a customer-management system" and "application development." However, "system development aimed at sales itself" is treated as out of scope, and the line is subtle. The key is whether you can explain in your business plan how the booking system contributes to "winning new customers and expanding sales channels," and for the final call, always confirm with the secretariat.

6. Designing the order around the 300,000-yen ceiling

It's precisely because of the "300,000-yen wall" that the order design is simple.

【推奨】小さく作って、公開して、回す
  1. 販路開拓に直結する最小構成（MVP）で発注
  2. ウェブサイト関連費は補助金30万円枠に収める設計
  3. 残りの枠（広報費など他費目）と組み合わせて申請
  4. 期間内に公開 → 販路開拓の取組を実際に開始

With a premise of one person × generative AI (Claude Code), the range of what you can build widens on the same budget. I myself, using AI as an implementation accelerator while guaranteeing quality with human verification gates, have achieved zero double-charging incidents in production on a payment platform. Even within a subsidy's limited frame, if you narrow to the essentials, "build small, launch fast, and run market development" is entirely realistic.

Here again are the two cash-flow points a buyer must nail:

• Paid in arrears: the subsidy is settled after the results report. Plan on the premise that you'll front the full amount with your own funds at least once.
• Disposal-restricted asset: a site or system built for 500,000 yen (excluding tax) or more normally can't be scrapped, transferred, or used for a different purpose for 5 years without the secretariat's approval. A rebuild itself (improvements or feature enhancements needed to achieve the purpose) doesn't count as disposal, but be careful if you're planning a major renewal or shutdown.

7. Schedule and application flow (20th round)

The 20th-round schedule is as follows (subject to change; confirm officially).

What buyers tend to overlook is Form 4 (the Business Support Plan). This subsidy presupposes that you "work on it with the support of the Society of Commerce and Industry / Chamber of Commerce and Industry," and you need to ask your local society or chamber to issue Form 4. Because Form 4's issuance deadline (December 4) comes before the application deadline (December 15), you need to work backwards and move early.

経営計画の策定
   ↓
商工会・商工会議所へ様式4の発行依頼（〜12/4）
   ↓
電子申請で提出（〜12/15 17:00）
   ↓
審査 → 交付決定（採択発表から概ね1〜2か月）
   ↓
補助事業の実施（発注・制作・公開・販路開拓）
   ↓
実績報告 → 補助金の精算払い（後払い）

8. Common misconceptions and failure patterns

Fit the subsidy into a design of "first draw the market-development picture, order a minimal site/system as the means, then launch it and run it," and even a solo owner can make good use of it. Conversely, if you start from "subsidy first" and try to build a whole rich site, you'll trip on all four points — the ceiling, the no-standalone-application rule, the market-development requirement, and payment in arrears.

I am not a registered IT-introduction support vendor, and I do not handle subsidy application filing on your behalf. This article is a neutral explanation to support the decision-making of buyers (businesses that want to build a system or site). For the program's details and the latest subsidy rate, ceilings, and schedule, always confirm against the official application guidelines. On top of that, if you're stuck on the order design — "for market development, what and how much should I build on a limited budget?" — I can help you sort it out together in a free consultation or DX assessment (not application support, but a discussion of what to build and in what priority).