diff --git a/internal/api/verify.go b/internal/api/verify.go
index ae0d05c42b..439c00c506 100644
--- a/internal/api/verify.go
+++ b/internal/api/verify.go
@@ -408,7 +408,13 @@ func (a *API) smsVerify(r *http.Request, conn *storage.Connection, user *models.
 
 		switch params.Type {
 		case smsVerification:
-			if terr := models.NewAuditLogEntry(config.AuditLog, r, tx, user, models.UserSignedUpAction, "", map[string]interface{}{
+			// A phone that is already confirmed belongs to an existing user,
+			// so this verification is a sign-in, not a signup.
+			action := models.UserSignedUpAction
+			if user.IsPhoneConfirmed() {
+				action = models.LoginAction
+			}
+			if terr := models.NewAuditLogEntry(config.AuditLog, r, tx, user, action, "", map[string]interface{}{
 				"provider": PhoneProvider,
 			}); terr != nil {
 				return terr
diff --git a/internal/api/verify_ott_parity_test.go b/internal/api/verify_ott_parity_test.go
index c48b60bbc8..20f1656624 100644
--- a/internal/api/verify_ott_parity_test.go
+++ b/internal/api/verify_ott_parity_test.go
@@ -226,6 +226,14 @@ func (ts *VerifyTestSuite) TestVerifyOTPParityPhoneFlows() {
 		Phone:          parityPhone,
 	}
 
+	phoneLoggedIn := otpParityOutcome{
+		Status:         http.StatusOK,
+		Action:         string(models.LoginAction),
+		PhoneConfirmed: true,
+		Email:          parityEmail,
+		Phone:          parityPhone,
+	}
+
 	phoneChanged := otpParityOutcome{
 		Status:         http.StatusOK,
 		Action:         string(models.UserModifiedAction),
@@ -242,6 +250,16 @@ func (ts *VerifyTestSuite) TestVerifyOTPParityPhoneFlows() {
 			requestBody: phoneOTPBody(smsVerification, parityPhone),
 			expected:    phoneSignedUp,
 		},
+		// An existing user signing in with an SMS code is a login. Only the
+		// verification that first confirms the phone is a signup.
+		"sms with a valid code signs a confirmed user in": {
+			seed: func(u *models.User) {
+				u.PhoneConfirmedAt = &now
+				ts.seedChallenge(u, models.ConfirmationToken, parityPhone, phoneHash, now, time.Hour)
+			},
+			requestBody: phoneOTPBody(smsVerification, parityPhone),
+			expected:    phoneLoggedIn,
+		},
 		"sms with an expired code is rejected": {
 			seed: func(u *models.User) {
 				ts.seedChallenge(u, models.ConfirmationToken, parityPhone, phoneHash, expired, -time.Hour)