A receipt confirms something the customer already bought. A promotion asks them to buy something. Put both in the same email and the classification needs another look.
Transactional vs marketing email: transactional messages fulfil an existing transaction or account need; marketing messages promote products or services. The actual content matters. US CAN-SPAM uses a primary-purpose test for mixed messages; UK PECR guidance treats a service message containing marketing as direct marketing. An automated trigger does not decide the category, and classification alone does not establish permission to send.
This guide covers US federal CAN-SPAM and UK PECR for ordinary ecommerce email. Other countries and additional privacy, sector and platform rules need their own assessment. The examples explain the tests; they are not legal advice on a particular send.
What makes an email transactional or marketing?
Under US CAN-SPAM, a transactional message can confirm an already-agreed purchase; commercial email primarily advertises or promotes a product or service. Under UK PECR guidance, purely administrative service messages contain no promotion. Adding marketing changes the assessment.
The US transactional categories are narrow. Other categories include product safety or recall information and specified notices about an ongoing account or subscription. Being a customer does not make every subsequent email transactional. The FTC explicitly warns against that assumption, including for subscriptions and memberships.
The ICO’s electronic-mail guidance describes purely administrative or customer-service messages without promotion as service messages. Adding advertising or marketing material changes that assessment.
| Illustrative message | What the content does | Classification starting point |
|---|---|---|
| Order confirmation containing the purchased items and payment details, with no promotion | Confirms an agreed purchase | US transactional category; UK administrative service message |
| Email offering a discount on a new purchase | Promotes another sale | Marketing; assess permission and opt-out duties |
| Receipt followed by a recommendation to buy accessories | Combines a transaction update with promotion | Apply the relevant mixed-content rule below |
These are content examples, not certifications for template names. “Order update” on the subject line cannot rescue a body built around selling another product.
A post-purchase flow can therefore contain different categories of message. Classify the receipt and the later cross-sell separately. They share a customer event, but they do different jobs.
Can you put promotions in a transactional email?
Under US CAN-SPAM, adding promotion requires the mixed-content primary-purpose test: a promotional subject line or transactional content not mainly at the beginning makes the message commercial. Under UK PECR guidance, adding marketing material makes a service message direct marketing, even if promotion is secondary. A US assessment does not establish a UK exemption.
US: apply the mixed-content primary-purpose test
For an email containing both commercial and transactional or relationship content, the FTC says its primary purpose is commercial if either:
- A recipient reasonably interpreting the subject line would expect advertising or promotion.
- The transactional or relationship content does not appear mainly at the beginning.
Keep both tests. A neutral subject line alone is insufficient; putting order details first alone does not overcome a promotional subject line.
The FTC gives an example with account information first and a brief promotion at the end, calling it most likely transactional or relationship. That is a qualified example, not blanket approval for promotional receipt footers.
Nor is “more service text than sales text” the stated test. If you are assessing commercial content mixed with material that is neither transactional nor commercial, the FTC gives a separate test involving how a reasonable recipient interprets the subject or body, including the promotion’s position, proportion and visual emphasis. First identify what kinds of content you actually have.
UK: marketing does not have to be the main purpose
The ICO says a purely administrative service message becomes direct marketing when advertising or marketing material is added. The administrative reason for sending it does not erase the promotional content.
For an illustrative receipt saying “Your order is confirmed” followed by “Buy the matching case,” assess the added recommendation as marketing. Moving that recommendation to the bottom does not supply the UK exemption that the US example might suggest.
A practical template choice is to keep the essential service message free of promotion and send an optional offer separately to an eligible marketing audience. This is a way to apply the rules, not a regulator-prescribed format. Separating the emails does not create permission for the promotional one.
Are abandoned-checkout emails and stock alerts transactional?
A reminder promoting an unpurchased basket is marketing under the US and UK content distinctions. A specifically requested stock alert can be UK solicited marketing; being requested does not make it transactional. Check the actual copy and request. A message about payment on an already-agreed order needs a separate assessment.
An abandoned-basket reminder: imagine a shopper who has not placed an order receiving “Complete your purchase.” That copy promotes a purchase. The fact that the shopper entered an address does not, by itself, establish an already-agreed transaction under the US category. Under the UK content distinction, it is promotional too.
That example does not cover every incomplete payment. A service message resolving payment on an already-agreed order requires assessment against that existing transaction and its actual copy. Avoid a rule saying every message triggered by an unfinished checkout has the same legal status.
The abandoned-cart guide explains what can trigger recovery. The trigger answers a different question from the classification or permission check.
A back-in-stock alert: imagine a person specifically asking for one email when a particular product returns. In UK guidance, marketing is solicited when someone specifically requests that message or type of information. An alert promoting that product can therefore be solicited marketing. Being requested does not turn it into a service receipt.
The ICO’s sending rules allow that specifically requested marketing without consent or a soft opt-in, while retaining sender-identification and opt-out-address duties. A later unrelated offer needs its own assessment; the alert request does not cover it automatically.
Keep the original request wording beside the alert template. “Tell me when this size returns” and “Send me your offers” describe different requests.
What changes for consent and unsubscribe?
US federal CAN-SPAM does not require prior opt-in for commercial email, but requires a marketing opt-out. UK unsolicited product marketing to individual subscribers needs consent or all products-and-services soft-opt-in conditions. UK solicited marketing still needs sender identification and an opt-out address. Gmail’s bulk-sender one-click rule for personal Gmail destinations is a separate requirement for marketing and promotional messages.
For US federal CAN-SPAM, the FTC confirms there is no prior opt-in requirement. Commercial messages still have duties, including accurate headers and subject lines, a valid postal address and a way to stop future marketing. Prior affirmative consent removes the ad-identification requirement, not the other commercial-email obligations. A purely transactional or relationship email remains subject to the rule against false or misleading routing information.
For UK unsolicited product-marketing email to individual subscribers, you need consent or every condition of the products-and-services soft opt-in. Those conditions include collecting the address directly during a sale or sale negotiation, promoting your own similar products or services, and offering an opt-out both at collection and in subsequent messages. Respect an opt-out. This summary is not the rule for every UK recipient type or charitable message.
For contact eligibility, use the guide to emailing people who never opted in. Here, the task is to give that check an accurately classified message.
There is also a mailbox-provider layer. In Gmail’s bulk-sender guidance for personal Gmail accounts, one-click unsubscribe applies to marketing and promotional messages; transactional messages are excluded from that requirement. Password resets and reservation confirmations are examples Google gives.
A footer link alone does not meet that header-based requirement. The one-click unsubscribe guide covers implementation. Google’s requirement is distinct from the legal tests above; a “transactional” setting in your sending software is not a substitute for either assessment.
What should you record before enabling a template?
Record the template version, trigger, subject and rendered body; the classification under applicable rules; the sending basis and evidence; opt-out handling; and the decision owner. Recheck when promotional content changes. The worksheet below is a suggested operational aid, not an official form or compliance certificate.
| Record | What to retain |
|---|---|
| Template and context | Version, trigger and the existing transaction or request, if any |
| Actual content | Subject line and rendered body, including recommendations and offer blocks |
| Classification | US primary-purpose assessment and UK service/direct-marketing assessment where applicable |
| Sending basis | Applicable recipient category, permission route and supporting evidence |
| Opt-out handling | What stops marketing, and how the required unsubscribe method works |
| Decision | Owner, approval date and changes that require another look |
Illustrative review: a store approves a plain order receipt. Later, someone adds a product-recommendation block. Reopen the classification against the new subject and body rather than inheriting the old receipt’s approval. If the team removes the promotion, record the resulting service version. If it keeps the promotion, resolve the marketing requirements before enabling that version.
Check every variant that changes the answer. An order-triggered email without an offer and the same template with a sales block are different content decisions. The record should make that difference visible to whoever edits the next version.
Frequently asked questions
Does an automated email count as transactional?
An automated trigger does not determine the US CAN-SPAM or UK PECR classification. Assess the actual content: a plain confirmation of an agreed purchase differs from an automated offer asking for another purchase. A flow may contain both kinds of message.
Can a customer unsubscribe from marketing and still receive a receipt?
Yes, where the receipt is genuinely transactional or administrative under the applicable rules. A marketing opt-out is not permission to keep promotions inside that receipt. Apply the US mixed-content test or the UK service-message distinction to the actual message before using that route.
Is a requested back-in-stock email still marketing?
It can be. Under UK PECR guidance, a specifically requested product alert can be solicited marketing. That route does not require consent or a soft opt-in for the requested message, but sender identity and a valid opt-out address remain required. It does not automatically cover later unrelated promotions.
Does using a separate subdomain make an email transactional?
No. A sending subdomain is not the content test under US CAN-SPAM or UK PECR. Classify the subject and body, assess the sending basis, then decide the technical setup. The subdomain guide addresses that separate infrastructure decision.