diff --git a/cmd/api/users.go b/cmd/api/users.go
index b77ae2e..abe100f 100644
--- a/cmd/api/users.go
+++ b/cmd/api/users.go
@@ -3,6 +3,7 @@ package main
 import (
 	"errors"
 	"net/http"
+	"time"
 
 	"gitea.local.lab/Lbenedar/greenlight/internal/data"
 	"gitea.local.lab/Lbenedar/greenlight/internal/validator"
@@ -52,8 +53,18 @@ func (app *application) registerUserHandler(w http.ResponseWriter, r *http.Reque
 		return
 	}
 
+	token, err := app.models.Tokens.New(user.ID, 3*24*time.Hour, data.ScopeActivation)
+	if err != nil {
+		app.serverErrorResponse(w, r, err)
+		return
+	}
+
 	app.background(func() {
-		err = app.mailer.Send(user.Email, "user_welcome.tmpl", user)
+		data := map[string]any{
+			"activationToken": token.Plaintext,
+			"userID":          user.ID,
+		}
+		err = app.mailer.Send(user.Email, "user_welcome.tmpl", data)
 		if err != nil {
 			app.logger.PrintError(err, nil)
 		}
diff --git a/internal/mailer/templates/user_welcome.tmpl b/internal/mailer/templates/user_welcome.tmpl
index 179cb38..683a73a 100644
--- a/internal/mailer/templates/user_welcome.tmpl
+++ b/internal/mailer/templates/user_welcome.tmpl
@@ -7,6 +7,13 @@ Thanks for signing up for a Greenlight account. We're excited to have you on boa
 
 For future reference, your user ID number is {{.ID}}.
 
+Please send a request to the `PUT /v1/users/activated` endpoint with the following JSON
+body to activate your account:
+
+{"token": "{{.activationToken}}"}
+
+Please note that this is a one-time use token and it will expire in 3 days.
+
 Thanks,
 
 The Greenlight Team
@@ -26,6 +33,12 @@ The Greenlight Team
     <p>Hi,</p>
     <p>Thanks for signing up for a Greenlight account. We're excited to have you on board!</p>
     <p>For future reference, your user ID number is {{.ID}}.</p>
+    <p>Please send a request to the <code>PUT /v1/users/activated</code> endpoint with the
+    following JSON body to activate your account:</p>
+    <pre><code>
+    {"token": "{{.activationToken}}"}
+    </code></pre>
+    <p>Please note that this is a one-time use token and it will expire in 3 days.</p>
     <p>Thanks,</p>
     <p>The Greenlight Team</p>
 </body>