seikyusho

Invoice automation for Japanese-style billing — on nothing but Google Workspace. Accepts invoice requests through a multilingual form, auto-generates PDF invoices (Qualified Invoice System and 源泉 withholding aware), and runs the approve/reject notification flow. No server, no SaaS, no database — one MIT-licensed Apps Script project. seikyusho（請求書）is Japanese for "invoice."

🌐 日本語 · 한국어 · 繁體中文

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Overview

A fully automated invoice issuance system for accepting requests from contractors, freelancers, or any external party.

• Applicants simply fill out a multilingual form (Japanese / English / Traditional Chinese / Spanish)
• Administrators receive an email, then click "Approve" or "Reject" on the sheet
• PDF generation, numbering, tax calculation, email notifications, and Drive archiving are all automatic

Built entirely on Google Workspace — no external services, servers, or databases required.

Features

• 🌐 Multilingual form (Japanese / English / Traditional Chinese / Spanish, switchable via URL param)
• 📄 3 PDF templates auto-selected (overseas resident / Japan w/o withholding / Japan with withholding)
• 🔢 Monthly sequential invoice numbering (e.g., 202605-001)
• 💴 Multi-currency (JPY / TWD / USD / EUR, extensible)
• 🧮 Automatic tax calculation (10% consumption tax, 10.21% / 20.42% withholding tax with 1M JPY threshold)
• 📧 3 types of automated emails:
  • On submission → admin receives notification with PDF attached
  • On approval → applicant receives approval notice (PDF attached, admin CC'd)
  • On rejection → applicant receives rejection notice (admin CC'd)
• ✏️ Email content editable from sheet ({{INVOICE_NO}} / {{APPLICANT_NAME}} placeholders supported)
• 🧾 Japanese Qualified Invoice System (Invoice Seido) support (toggle registration number display)
• 🔁 Withholding tax can be added post-submission (changing the sheet auto-regenerates the PDF)
• 📂 PDFs auto-saved to a Drive folder (easy bulk sharing with accountants)

File Structure

File	Purpose
appsscript.json	Apps Script manifest (permissions, timezone)
Setup.gs	Initial setup, migrations, usage sheet generation
Code.gs	Form handler, PDF generation, mail sender, triggers
index.html	Applicant-facing web form
style.html	Form CSS (responsive)
script.html	Form JavaScript
i18n.html	Translation dictionary (日本語 / English / 繁體中文 / Español)

Prerequisites

• Google account (personal or Workspace)
• A browser (for the admin who sets it up)
• At least one email address to receive notifications

Setup

Three ways to deploy. The easiest is to copy. Prefer to install from the GitHub source — e.g. company policy or you'd rather not copy a third party's Sheet? Use the manual or clasp path instead. Either way, your data, PDFs and emails stay entirely inside your account.

🚀 Option A: Make a copy of the Google Sheet (easiest, ~1 min)

1. Open Make a copy of the Google Sheet and click "Make a copy" — the whole system lands in your own Drive.
2. Open your copy, then run the menu "請求書 → 🚀 初期セットアップ（最初に1回）" → authorize (Drive / Sheet / Mail / Trigger).
3. Fill company info + notification email in the 設定 (Settings) sheet.
4. Deploy → New deployment → Web app (Execute as: me / Access: anyone) → paste the /exec URL into form_url in Settings, then re-run populateUsageSheet.
5. Share the form URL with applicants.

🔒 The copied code is the same MIT-licensed code as on GitHub — no third-party server is involved.

📦 Option B: Manual copy/paste from the GitHub source (~20 min)

Step 1. Create Apps Script project

1. Open Google Apps Script
2. Click "New project"
3. Rename it (e.g., "Invoice System")

Step 2. Copy 7 files

Copy each file from this repo into the Apps Script editor (1:1):

Local	Apps Script
appsscript.json	appsscript.json (enable "Show appsscript.json" in settings)
Setup.gs	New file "Setup"
Code.gs	Overwrite the default Code.gs
index.html	New HTML file "index"
style.html	New HTML file "style"
script.html	New HTML file "script"
i18n.html	New HTML file "i18n"

Step 3. Run initial setup (one function does it all)

💡 Recommended: Select setup from the function dropdown → Run. It runs everything in this step (create sheet, wire triggers, generate the usage sheet) in the right order, idempotently. Grant permissions on first run (Drive / Sheet / Mail / Trigger scopes), then skip to Step 4.

Only if you prefer to run them individually:

1. runSetup — a spreadsheet is auto-created and SPREADSHEET_ID is saved to script properties
2. installSheetMenuTrigger — enables the custom menu
3. installStatusEditTrigger — wires approval/rejection/withholding-change auto-handlers
4. populateUsageSheet — generates the "Usage" sheet

Step 4. Fill in company info in the "設定" (Settings) sheet

Open the spreadsheet, navigate to the 設定 (Settings) tab, and fill in fields (see Configuration).

notification_email (admin's address) is required.

Step 5. Deploy as Web App

1. In Apps Script: Deploy → New deployment
2. Type: Web app
3. Settings:
   • Execute as: Me
   • Who has access: Anyone
4. Copy the web app URL (ends in /exec)

Step 6. Paste the URL into "設定"

Set form_url to the URL from Step 5.

Step 7. Regenerate the usage sheet

Run populateUsageSheet again — the URL will now appear in the guide.

Step 8. Share the form URL with applicants

Done 🎉

⚡ Option C: Push via clasp from the GitHub source (~5 min)

# Install clasp once
npm install -g @google/clasp
clasp login

# Clone & push
git clone https://github.com/CVERInc/seikyusho.git
cd seikyusho

clasp create --type standalone --title "Invoice System"
clasp push -f

# Then run setup() once in Apps Script, fill Settings, deploy as web app

Configuration

Edit these in the 設定 (Settings) sheet:

key	Required	Description
company_name_ja-JP	✅	Recipient name (Japanese)
company_name_en-US		Recipient name (English)
company_name_zh-TW		Recipient name (Traditional Chinese / Taiwan)
company_name_es-ES		Recipient name (Spanish)
company_address	✅	Registered address
corporate_number		Corporate number (13 digits, only if shown)
representative		Representative name
notification_email	✅	Admin's notification email
form_url		Deployed web app URL (after deployment)
qualified_invoice_number		Qualified invoice issuer number (T + 13 digits)
show_corporate_number		Show corporate number on PDF (yes/no, default no)
email_subject_approved		Subject for approval mail
email_body_approved		Body for approval mail
email_subject_rejected		Subject for rejection mail
email_body_rejected		Body for rejection mail
consumption_tax_rate		Consumption tax rate (default 0.10)
withholding_tax_rate		Withholding tax rate (default 0.1021)
withholding_threshold		Withholding tax threshold (default 1,000,000 JPY)
withholding_tax_rate_over		Withholding rate above threshold (default 0.2042)
pdf_folder_id		Drive folder ID for PDFs (auto-created)

Workflow

flowchart TD
    A[Applicant submits the form] --> B[Logged on the sheet<br/>status: pending]
    B --> C[Invoice number assigned]
    C --> D[PDF auto-generated<br/>template picked by residency / withholding]
    D --> E[Admin notified by email<br/>PDF attached]
    E --> F{Admin decides}
    F -->|approved| G[Approval mail to applicant<br/>PDF attached, admin CC'd]
    F -->|rejected| H[Rejection mail to applicant<br/>admin CC'd]
    F -->|withholding changed| I[PDF regenerated<br/>same number, old PDF trashed]
    I --> F

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In short: Applicant submits → Sheet logs as pending → PDF generated → Admin notified → Admin sets approved or rejected on sheet → Applicant gets corresponding email automatically.

FAQ

Q1. Will I hit Apps Script quotas?

For typical usage (tens to hundreds per month), no. Workspace accounts allow 1,500 emails/day and Drive ops are effectively unlimited.

Q2. How do I change the PDF template layout?

Edit the TPL_海外 / TPL_源泉あり / TPL_源泉なし sheets directly.

Header positions (品名/数量/単価/金額/小計) are auto-detected, so you can move them freely.

Keep the {{APPLICANT_NAME}}, {{INVOICE_NO}}, etc. placeholders intact.

Q3. How do I customize email text?

Edit email_subject_approved / email_body_approved / email_subject_rejected / email_body_rejected in the Settings sheet. Changes apply immediately.

Use Cmd/Ctrl+Enter to insert line breaks within a cell.

Q4. Does it support the Japanese Qualified Invoice System (Invoice Seido)?

Yes. Fill qualified_invoice_number (T + 13 digits) and your PDF will show "登録番号: T..." at the bottom.

If you're not registered, leave show_corporate_number as no (the default) — no misleading numbers will appear.

Q5. How do I clean up test data?

In the spreadsheet menu: 請求書 → ❌ 全テストデータ削除. Submissions, counter, and Drive PDFs are cleared in one shot (with confirmation).

Contributing

Issues and PRs welcome. See CONTRIBUTING.md for the full guide.

• 🐛 Bug reports → include reproduction steps
• 💡 Feature requests → Discussions or Issues
• 🌐 Translations → Adding a new language guide (8 steps)
• 💴 New currency → Adding a new currency guide

License

MIT License

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Built with ❤️ on Google Apps Script