diff --git a/invitation.go b/invitation.go
index 86afef5..d94a6bc 100644
--- a/invitation.go
+++ b/invitation.go
@@ -11,6 +11,7 @@ type Invitation struct {
 	Revoked        bool            `json:"revoked,omitempty"`
 	Status         string          `json:"status"`
 	URL            string          `json:"url,omitempty"`
+	ExpiresAt      *int64          `json:"expires_at"`
 	CreatedAt      int64           `json:"created_at"`
 	UpdatedAt      int64           `json:"updated_at"`
 }
diff --git a/invitation/client.go b/invitation/client.go
index 87c70f1..4ac0099 100644
--- a/invitation/client.go
+++ b/invitation/client.go
@@ -64,6 +64,7 @@ type CreateParams struct {
 	RedirectURL    *string          `json:"redirect_url,omitempty"`
 	Notify         *bool            `json:"notify,omitempty"`
 	IgnoreExisting *bool            `json:"ignore_existing,omitempty"`
+	ExpiresInDays  *int64           `json:"expires_in_days,omitempty"`
 }
 
 // Create adds a new identifier to the allowlist.
diff --git a/invitation/invitation_test.go b/invitation/invitation_test.go
index a2b2abd..9f8e5fb 100644
--- a/invitation/invitation_test.go
+++ b/invitation/invitation_test.go
@@ -110,6 +110,33 @@ func TestInvitationCreate(t *testing.T) {
 	require.Equal(t, emailAddress, invitation.EmailAddress)
 }
 
+func TestInvitationCreateWithExpiration(t *testing.T) {
+	emailAddress := "foo@bar.com"
+	id := "inv_123"
+	expiresInDays := int64(7)
+	expiresAt := int64(1700000000)
+	clerk.SetBackend(clerk.NewBackend(&clerk.BackendConfig{
+		HTTPClient: &http.Client{
+			Transport: &clerktest.RoundTripper{
+				T:      t,
+				In:     json.RawMessage(fmt.Sprintf(`{"email_address":"%s","expires_in_days":%d}`, emailAddress, expiresInDays)),
+				Out:    json.RawMessage(fmt.Sprintf(`{"id":"%s","email_address":"%s","expires_at":%d}`, id, emailAddress, expiresAt)),
+				Method: http.MethodPost,
+				Path:   "/v1/invitations",
+			},
+		},
+	}))
+
+	invitation, err := Create(context.Background(), &CreateParams{
+		EmailAddress:  emailAddress,
+		ExpiresInDays: &expiresInDays,
+	})
+	require.NoError(t, err)
+	require.Equal(t, id, invitation.ID)
+	require.Equal(t, emailAddress, invitation.EmailAddress)
+	require.Equal(t, expiresAt, *invitation.ExpiresAt)
+}
+
 func TestInvitationCreate_Error(t *testing.T) {
 	clerk.SetBackend(clerk.NewBackend(&clerk.BackendConfig{
 		HTTPClient: &http.Client{