You sit down to write a Japanese business email. You want to say “I have attached the invoice.” Easy enough — but which word do you use? 添付（てんぷ）? 送付（そうふ）? And what about when you mail a physical document in an envelope, or include a pamphlet inside a shipped package? Japanese has a different word for each of these situations, and mixing them up is one of the most common mistakes learners make when writing professional Japanese.
This guide breaks down all four words — 添付, 同封（どうふう）, 同梱（どうこん）, and 送付 — so you can choose the right one every time, whether you are writing an email, mailing a letter, or dealing with an EC shopping return.
| Word | Reading | Core meaning | Used for |
|---|---|---|---|
| 添付 | てんぷ | Attach | Files or documents attached to an email or form |
| 同封 | どうふう | Enclose in the same envelope | Papers, cards, or documents placed inside an envelope |
| 同梱 | どうこん | Include in the same package | Items placed inside a box or parcel alongside a product |
| 送付 | そうふ | Send formally | Formal sending of documents or items by any means |
Quick Answer: 添付 vs 同封 vs 同梱 vs 送付
添付 means attach
添付（てんぷ） is the word for attaching a digital file to an email, or for attaching a document to a form. It lives almost entirely in the digital world — or in bureaucratic language where a physical document is “attached” as an addendum. If you are clicking a paperclip icon in your email client, the word you want is 添付.
同封 means enclose in the same envelope
同封（どうふう） literally means “enclosed in the same seal” — as in, inside the same envelope (封筒, ふうとう). When you mail a letter and slip a return envelope or a brochure inside the same envelope, those extra items are 同封 items. The word signals that everything arrived together, sealed in one envelope.
同梱 means include in the same package or box
同梱（どうこん） is the package version of 同封. Where 同封 is for envelopes, 同梱 is for boxes, parcels, and shipping containers. When an EC store ships your order and includes an invoice slip or a coupon inside the box, that slip is said to be 同梱 in the package. The character 梱 (こん) refers to a crate or packing case.
送付 means send formally
送付（そうふ） describes the act of formally sending something — documents, files, or goods — to a recipient. It does not specify the method (email, post, courier) or the container (envelope, box). It is the polite umbrella verb for “send,” most at home in business correspondence.
How English “send” and “attach” split into four words in Japanese
In English, “send” covers everything — you send an email, send a package, send a document. Japanese makes finer distinctions based on what you are sending, how it travels, and where it sits relative to other items. Think of it this way:
- Attaching to email/form → 添付
- Placing inside an envelope → 同封
- Placing inside a package/box → 同梱
- Formally sending anything → 送付
What Does 添付 Mean?
添付 as file/document attach (email and forms)
添付（てんぷ） comes from 添（そ）える (to add alongside) + 付（つ）ける (to attach). In modern business Japanese, it almost always refers to digital attachments. You will see it constantly in office email, government forms, and online submission systems. It can also appear in formal writing to mean a physically appended document, but the email usage is by far the most common.
ファイルを添付する — email attachments
The standard pattern is ファイルを添付する or 〜を添付いたします in polite business email.
| Japanese | English |
|---|---|
| ファイルを添付しました。 | I have attached the file. |
| ご確認いただけますよう、資料を添付いたします。 | I am attaching the materials for your review. |
| 添付のファイルをご参照ください。 | Please refer to the attached file. |
| 履歴書を添付しております。 | I have attached my resume. |
添付書類 — attached documents
添付書類（てんぷしょるい） means “attached documents” and appears frequently on official forms and application checklists. When a government or company asks you to submit supporting documents along with an application, those supporting documents are the 添付書類.
Example: 添付書類：住民票のコピー、写真1枚 — Attached documents: a copy of your resident certificate, one photograph.
添付漏れ — forgetting to attach
One of the most embarrassing office mistakes is 添付漏れ（てんぷもれ） — sending an email that says “I have attached the file” but forgetting to actually attach it. This is so common in Japanese workplaces that there is a set phrase for apologizing for it:
先ほどのメールに添付漏れがございました。大変失礼いたしました。改めてファイルを添付してお送りいたします。
I forgot to attach the file in my previous email. I sincerely apologize. I am resending with the file attached.
Business email examples
Here are complete, natural business email phrases using 添付:
| Japanese phrase | English meaning | Register |
|---|---|---|
| ファイルを添付いたします。 | I am attaching the file. | Polite business |
| 添付ファイルをご確認ください。 | Please check the attached file. | Standard business |
| 添付の通りご確認ください。 | Please check as per the attachment. | Formal business |
| 添付漏れをお詫び申し上げます。 | I apologize for forgetting to attach the file. | Formal apology |
YukaSo 添付 is basically only for email and digital files? I always thought it could mean enclosing something in an envelope too.
ReiGreat question! 添付 can technically appear in written documents to mean “appended” — like an appendix — but for physical envelopes, Japanese people use 同封 instead. If you write 添付 in a postal mail context, it sounds unnatural. Save 添付 for email and forms.
送付 — Formally Sending Documents or Items
送付 as formal sending
送付（そうふ） is built from 送（おく）る (to send) + 付（ふ）ける (to deliver/affix), giving a nuance of “sending and delivering” something formally. Unlike everyday words like 送る or 渡す (わたす), 送付 belongs to the business and administrative register. You would not use it in a casual text to a friend — it would sound oddly stiff. But in a business email or an official letter, it is exactly right.
書類を送付する
The most common collocation is 書類を送付する（しょるいをそうふする） — to send documents formally. This can refer to postal mail, email, fax, or courier, since 送付 does not specify the medium.
必要書類を送付いたします。 — I will formally send the required documents.
請求書を送付する
請求書（せいきゅうしょ）を送付する — to send an invoice — is extremely common in B2B business Japanese. You will see this phrase in accounting emails and automated billing systems.
今月分の請求書を送付いたしますので、ご確認のほどよろしくお願いいたします。
I am sending this month’s invoice, so I would appreciate your review.
送付先 — destination/recipient
送付先（そうふさき） means the destination or recipient address for a formal delivery. You will see this on forms asking for a delivery or mailing address.
Example on a form: 送付先住所をご記入ください。 — Please fill in the delivery address.
送付状 — cover letter/transmittal note
A 送付状（そうふじょう） is a transmittal letter or cover note that accompanies documents sent by post or fax. It identifies what is being sent, who is sending it, and sometimes includes a brief greeting. In English, you might call it a cover sheet or transmittal memo. When you mail a contract or application to a company, you typically include a 送付状 at the front.
送付いたします in business email
| Japanese | English |
|---|---|
| 資料を送付いたします。 | I will send the materials to you. |
| 本日、契約書を送付いたしました。 | I have sent the contract today. |
| 後日、正式な書類を送付いたします。 | I will send the official documents at a later date. |
| 送付先をご確認ください。 | Please confirm the delivery address. |
添付 vs 送付
Attach to email/form vs send formally
These two words are often confused because both appear in business emails about documents. The key distinction is this: 添付 describes what you do to a file (attach it), while 送付 describes the act of sending the whole email or package. In a single email, you might use both — you 添付 the file and then 送付 the email.
資料を添付する vs 書類を送付する
| 添付する | 送付する | |
|---|---|---|
| What it describes | The act of attaching (digital) | The act of sending formally |
| Medium | Email, online form | Any (email, post, fax, courier) |
| Subject | File, document attachment | Documents, items, packages |
| Register | Business standard | Business/formal |
| Example | ファイルを添付します | 書類を送付します |
Email vs postal/courier examples
Email context — use 添付:
資料を添付いたしますので、ご確認ください。
I have attached the materials, so please take a look.
Postal/courier context — use 送付:
本日、書類を郵送にて送付いたします。
I will send the documents by post today.
When both appear in the same email
It is perfectly natural to use both in the same email when you are attaching a digital copy and also mailing a physical original:
契約書のPDFを添付いたします。原本は後日郵送にて送付いたします。
I am attaching the PDF of the contract. I will send the original by post at a later date.
Common mistakes
- Wrong: 書類を送付しました（when you only emailed a PDF attachment — 添付 is more precise here）
- Wrong: ファイルを添付いたします + 送付先をご連絡ください（mixing digital 添付 with postal 送付先 without clarifying which is which）
- Note: 送付 is not wrong for email sending, but it feels redundant when 添付 already describes the attachment. Use 送付 for the overall act of dispatching, not for the file itself.
同封 vs 同梱
Envelope vs package — the key distinction
This pair trips up learners who treat them as interchangeable. The rule is simple and physical: 同封（どうふう）is for envelopes; 同梱（どうこん）is for boxes and packages.
- 封（ふう）in 同封 = seal / envelope → flat items in an envelope
- 梱（こん）in 同梱 = packing crate / bundled items → items in a box or parcel
封筒に同封する — enclosing in an envelope
When you physically place a document, card, or leaflet inside the same envelope as your letter, you use 同封.
| Japanese | English |
|---|---|
| 返信用封筒を同封いたします。 | I am enclosing a return envelope. |
| チラシを同封しましたので、ご参照ください。 | I have enclosed a flyer, so please take a look. |
| 同封の書類をご確認ください。 | Please check the enclosed documents. |
| お手紙に名刺を同封しております。 | I have enclosed my business card with the letter. |
商品に同梱する — including in a product package
When an EC store ships a product and places a receipt, instruction manual, or coupon inside the box along with the item, those materials are 同梱.
| Japanese | English |
|---|---|
| 納品書を同梱しております。 | We have included the delivery slip in the package. |
| 同梱の取扱説明書をご確認ください。 | Please check the instruction manual included in the package. |
| お買い上げありがとうございます。同梱のクーポンをご利用ください。 | Thank you for your purchase. Please use the enclosed coupon. |
| 同梱不可の商品がございます。 | There are items that cannot be included in the same package. |
返信用封筒を同封する
One of the most common uses of 同封 is with 返信用封筒（へんしんようふうとう） — a self-addressed return envelope. When companies or government offices want you to mail something back, they often enclose one for your convenience:
返信用封筒を同封いたしますので、ご記入の上ご返送ください。
I am enclosing a return envelope, so please fill it out and send it back.
同梱物 / 同封物 in EC and business
同梱物（どうこんぶつ） refers to the items included inside a shipped package. 同封物（どうふうぶつ） refers to items enclosed inside an envelope. Both are nouns you will see on checklists and packing slips:
- 同梱物リスト — list of items included in the package
- 同封物一覧 — list of items enclosed in the envelope
Common mistakes
- Wrong: 商品に同封しております (for items in a box — use 同梱)
- Wrong: 手紙に同梱しております (for items in an envelope — use 同封)
- Tip: Ask yourself: is it flat and in an envelope (同封) or bulky and in a box (同梱)?
YukaSo if I order something from a Japanese online shop and there’s a thank-you card inside the box, that card is 同梱 — not 同封?
ReiExactly right! Even though the thank-you card is a flat piece of paper, because it is inside a shipping box or parcel rather than inside an envelope, it is 同梱. The distinction is box vs envelope, not paper vs object.
同封 vs 送付
Enclose inside vs send as an action
同封 describes the spatial relationship — something is placed inside the same envelope. 送付 describes the action of sending. They answer different questions: 同封 answers “where is the document?”, and 送付 answers “how is it being delivered?” You can use both in the same sentence to be thorough.
書類を同封する vs 書類を送付する
| 同封する | 送付する | |
|---|---|---|
| Meaning | Enclose inside the same envelope | Formally send (by any means) |
| Focus | Location (inside the envelope) | Action (the sending itself) |
| Medium required | Must be an envelope | No specific medium |
| Example | 書類を同封しました | 書類を送付しました |
郵送いたします
Related to both 同封 and 送付 is 郵送（ゆうそう）, which specifically means sending by post. When you use 郵送 together with 同封, you paint a full picture:
書類を同封の上、郵送いたします。
I will enclose the documents and send them by post.
This phrasing is very natural and frequently used in business correspondence when mailing physical documents.
送付書類 list
A 送付書類（そうふしょるい） is the list of documents being formally sent. You will see this heading on transmittal letters (送付状) — it tells the recipient exactly what has been sent:
送付書類：
1. 見積書 1部
2. カタログ 1部
Documents sent: Estimate (1 copy), Catalogue (1 copy)
Natural business phrasing
| Situation | Natural Japanese | English |
|---|---|---|
| Mailing a letter with a document inside | 書類を同封の上、郵送いたします。 | I will enclose the documents and send by post. |
| Formally sending documents (any method) | 書類を送付いたします。 | I will send the documents formally. |
| Confirming enclosed items | 同封の書類をご確認ください。 | Please check the enclosed documents. |
| Mailing with a return envelope | 返信用封筒を同封いたします。 | I am enclosing a return envelope. |
Related Sending Words You Should Know
郵送（ゆうそう）— send by post
郵送 specifically means sending via postal mail (Japan Post / 郵便). It contrasts with courier services or digital delivery. When a form says 郵送にてお送りください, it means the post office, not a courier or email.
発送（はっそう）— dispatch, ship
発送 is the moment of dispatching — when an item leaves the sender’s hands. EC stores use this word when your order leaves the warehouse: ご注文の商品を発送いたしました (We have shipped your order). It focuses on the departure, not the arrival.
配送（はいそう）— delivery/distribution
配送 covers the distribution and delivery process — getting items from the warehouse or post to the recipient. It is often used for the logistics side: 配送業者（はいそうぎょうしゃ） = delivery company, 配送状況 = delivery status/tracking.
別送（べっそう）— send separately
別送 means sending something as a separate delivery, rather than together with the main shipment. When customs or logistics require it, or when the item is too large to include in the main package, you use 別送: 別途、書類を別送いたします (I will send the documents separately).
同封物（どうふうぶつ）— enclosed items
同封物 is the noun for items enclosed in an envelope — the things that are 同封. A cover letter might say: 同封物：履歴書、職務経歴書、各1部 (Enclosed items: resume, work history — one copy each).
同梱物（どうこんぶつ）— included items in package
同梱物 is the noun for items included in a shipping package. EC stores list 同梱物 on packing slips: 同梱物：商品1点、納品書1枚、クーポン1枚 (Included in package: 1 product, 1 delivery slip, 1 coupon).
| Word | Reading | Meaning | Context |
|---|---|---|---|
| 郵送 | ゆうそう | Send by post | Japan Post / postal mail |
| 発送 | はっそう | Dispatch, ship | EC order departure notification |
| 配送 | はいそう | Delivery, distribution | Logistics, tracking status |
| 別送 | べっそう | Send separately | Separate shipment from main delivery |
| 同封物 | どうふうぶつ | Enclosed items (envelope) | Cover letter checklist |
| 同梱物 | どうこんぶつ | Included items (package) | EC packing slip |
Decision Rule: Which Word Should You Use?
Is it a file or document being attached to an email or form? → 添付
If you are clicking “Attach file” in your email, or if an online form asks you to upload a document, the word is 添付. The key marker is digital — it is not physically going anywhere.
Is it something enclosed in the same envelope? → 同封
If you are sliding a document, card, or brochure into an envelope alongside your letter, use 同封. The container is an envelope (封筒), and everything travels sealed together.
Is it something included in the same package or box? → 同梱
If you are packing an invoice, manual, or gift card inside a shipping box alongside a product, use 同梱. The container is a box or parcel, and the item is bundled with the main goods.
Are you formally sending documents or items? → 送付
If you are describing the overall formal act of sending — by email, post, fax, or courier — use 送付. It does not specify the container or method, just that something is being delivered formally.
Quick flowchart
Are you attaching a digital file to an email or form?
YES → 添付（てんぷ）
NO ↓
Is the item going inside an envelope (封筒)?
YES → 同封（どうふう）
NO ↓
Is the item going inside a box or shipping package?
YES → 同梱（どうこん）
NO ↓
Are you formally sending documents or items (any method)?
YES → 送付（そうふ）These words are not mutually exclusive. A single business transaction might involve all four: you 添付 a PDF invoice to an email, then 同封 a paper copy in an envelope, and 同梱 a sample product in the package — all of which you 送付 to the client.
Looking to practice your Japanese business communication with a real tutor? italki connects you with professional Japanese teachers and community tutors who can help you master polite business email phrasing, formal vocabulary, and natural written Japanese. Even one lesson focused on 送付状 writing or email etiquette can save you from an awkward moment at work.
Quick Quiz
Choose the correct word (添付 / 同封 / 同梱 / 送付) for each situation.
1. You are emailing your manager a report. You click the paperclip icon and select the PDF. You write: “レポートを___いたします。”
2. You receive a package from an online shop. Inside the box, there is a thank-you card. The shop describes the card as “___のカード”.
3. You are mailing a contract to a client by post. You slip a brochure into the envelope alongside the contract. You write: “パンフレットを___いたします。”
4. You are writing a formal letter informing a client that you will send them the requested documents. You write: “必要書類を___いたします。”
5. The application form tells you to upload a scanned copy of your ID. The field is labeled “身分証明書の___ファイル”.
6. An EC store emails you: “ご注文の商品を発送いたしました。インボイスは___しております。” (The invoice is inside the shipping box.)
Answers:
1. 添付 — You are attaching a digital file to an email. → レポートを添付いたします。
2. 同梱 — The card is inside a shipping box. → 同梱のカード。
3. 同封 — The brochure is going inside an envelope. → パンフレットを同封いたします。
4. 送付 — You are formally sending documents (any method). → 必要書類を送付いたします。
5. 添付 — The form asks you to upload a digital file. → 身分証明書の添付ファイル。
6. 同梱 — The invoice is inside the shipping box. → インボイスは同梱しております。
Have you ever mixed up 添付 and 同封 in a Japanese email or letter? Share your experience in the comments below — questions about specific business email phrases are very welcome!
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