diff --git a/services/tickets/zendesk/service.go b/services/tickets/zendesk/service.go
index 20f4c5e25..de9a0e7c9 100644
--- a/services/tickets/zendesk/service.go
+++ b/services/tickets/zendesk/service.go
@@ -80,23 +80,27 @@ func NewService(rtCfg *runtime.Config, httpClient *http.Client, httpRetries *htt
 // Open opens a ticket which for mailgun means just sending an initial email
 func (s *service) Open(session flows.Session, topic *flows.Topic, body string, assignee *flows.User, logHTTP flows.HTTPLogCallback) (*flows.Ticket, error) {
 	ticket := flows.OpenTicket(s.ticketer, topic, body, assignee)
+
+	contact := session.Contact()
+	if contact == nil {
+		return nil, fmt.Errorf("session contact is nil")
+	}
+
 	contactDisplay := session.Contact().Format(session.Environment())
 	contactUUID := string(session.Contact().UUID())
 
+	var trace *httpx.Trace
 	var phoneNumber string
-	urn := session.Contact().PreferredURN().URN()
-	if urn.Scheme() == "whatsapp" {
-		phoneNumber = string(session.Contact().PreferredURN().URN().Path())
+	preferredURN := contact.PreferredURN()
+	if preferredURN != nil && preferredURN.URN().Scheme() == "whatsapp" {
+		phoneNumber = string(preferredURN.URN().Path())
 	}
 
-	user, trace, err := s.restClient.SearchUser(contactUUID)
-	if trace != nil {
-		logHTTP(flows.NewHTTPLog(trace, flows.HTTPStatusFromCode, s.redactor))
-	}
-	if err != nil && trace.Response.StatusCode != http.StatusNotFound {
+	user, err := s.searchUserWithIdentities(contactUUID, phoneNumber, logHTTP)
+	if err != nil && user == nil {
 		return nil, err
 	}
-	if trace.Response.StatusCode == http.StatusNotFound || user == nil {
+	if user == nil {
 		newUser := &User{
 			Name:       contactDisplay,
 			ExternalID: contactUUID,
@@ -197,16 +201,18 @@ func (s *service) Open(session flows.Session, topic *flows.Topic, body string, a
 	if trace != nil {
 		logHTTP(flows.NewHTTPLog(trace, flows.HTTPStatusFromCode, s.redactor))
 	}
-	if err != nil && trace.Response.StatusCode != http.StatusNotFound {
+	if err != nil {
 		return nil, err
 	}
 
-	_, trace, err = s.restClient.MergeUser(user.ID, unmergedUser.ID)
-	if trace != nil {
-		logHTTP(flows.NewHTTPLog(trace, flows.HTTPStatusFromCode, s.redactor))
-	}
-	if err != nil && trace.Response.StatusCode != http.StatusNotFound {
-		return nil, err
+	if unmergedUser != nil {
+		_, trace, err = s.restClient.MergeUser(user.ID, unmergedUser.ID)
+		if trace != nil {
+			logHTTP(flows.NewHTTPLog(trace, flows.HTTPStatusFromCode, s.redactor))
+		}
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return ticket, nil
@@ -402,3 +408,49 @@ func (s *service) convertAttachments(attachments []utils.Attachment) ([]string,
 	}
 	return fileURLs, nil
 }
+
+func (s *service) searchUserWithIdentities(contactUUID string, phoneNumber string, logHTTP flows.HTTPLogCallback) (*User, error) {
+	fetchUser := func(identifier string) (*User, error) {
+		if identifier == "" {
+			return nil, nil
+		}
+		user, trace, err := s.restClient.SearchUser(identifier)
+		if trace != nil {
+			logHTTP(flows.NewHTTPLog(trace, flows.HTTPStatusFromCode, s.redactor))
+		}
+		if err != nil && trace.Response.StatusCode != http.StatusNotFound {
+			return nil, err
+		}
+		return user, nil
+	}
+
+	userContactUUID, err := fetchUser(contactUUID)
+	if err != nil {
+		return nil, err
+	}
+
+	userPhoneNumber, err := fetchUser(phoneNumber)
+	if err != nil {
+		return nil, err
+	}
+
+	switch {
+	case userContactUUID == nil && userPhoneNumber == nil:
+		return nil, nil
+	case userContactUUID != nil && userPhoneNumber == nil:
+		return userContactUUID, nil
+	case userPhoneNumber != nil && userContactUUID == nil:
+		return userPhoneNumber, nil
+	case userContactUUID.ID == userPhoneNumber.ID:
+		return userContactUUID, nil
+	default:
+		mergedUser, trace, err := s.restClient.MergeUser(userContactUUID.ID, userPhoneNumber.ID)
+		if trace != nil {
+			logHTTP(flows.NewHTTPLog(trace, flows.HTTPStatusFromCode, s.redactor))
+		}
+		if err != nil && trace.Response.StatusCode != http.StatusNotFound {
+			return nil, err
+		}
+		return mergedUser, nil
+	}
+}