diff --git a/src/api/api.go b/src/api/api.go
index e9816790..05fbcfac 100644
--- a/src/api/api.go
+++ b/src/api/api.go
@@ -123,6 +123,11 @@ type Error struct {
 	Msg string `json:"error"`
 }
 
+type SendMessageError struct {
+	Msg string `json:"error"`
+	ChallengeTokens []string `json:"challenge_tokens,omitempty"`
+}
+
 type CreateGroupResponse struct {
 	Id string `json:"id"`
 }
@@ -138,7 +143,7 @@ type TrustIdentityRequest struct {
 }
 
 type SendMessageResponse struct {
-	Timestamp string `json:"timestamp"`
+	Timestamp       string   `json:"timestamp"`
 }
 
 type TrustModeRequest struct {
@@ -367,7 +372,7 @@ func (a *Api) Send(c *gin.Context) {
 // @Accept  json
 // @Produce  json
 // @Success 201 {object} SendMessageResponse
-// @Failure 400 {object} Error
+// @Failure 400 {object} SendMessageError
 // @Param data body SendMessageV2 true "Input Data"
 // @Router /v2/send [post]
 func (a *Api) SendV2(c *gin.Context) {
@@ -401,15 +406,19 @@ func (a *Api) SendV2(c *gin.Context) {
 		return
 	}
 
-	timestamps, err := a.signalClient.SendV2(
+	data, err := a.signalClient.SendV2(
 		req.Number, req.Message, req.Recipients, req.Base64Attachments, req.Sticker,
 		req.Mentions, req.QuoteTimestamp, req.QuoteAuthor, req.QuoteMessage, req.QuoteMentions, req.TextMode, req.EditTimestamp)
 	if err != nil {
+		if data != nil {
+			c.JSON(400, SendMessageError{Msg: err.Error(), ChallengeTokens: (*data)[0].ChallengeTokens})
+			return
+		}
 		c.JSON(400, Error{Msg: err.Error()})
 		return
 	}
 
-	c.JSON(201, SendMessageResponse{Timestamp: strconv.FormatInt((*timestamps)[0].Timestamp, 10)})
+	c.JSON(201, SendMessageResponse{Timestamp: strconv.FormatInt((*data)[0].Timestamp, 10)})
 }
 
 func (a *Api) handleSignalReceive(ws *websocket.Conn, number string, stop chan struct{}) {
diff --git a/src/client/client.go b/src/client/client.go
index 6ad9b42b..8ac2f221 100644
--- a/src/client/client.go
+++ b/src/client/client.go
@@ -161,7 +161,8 @@ type SignalCliIdentityEntry struct {
 }
 
 type SendResponse struct {
-	Timestamp int64 `json:"timestamp"`
+	Timestamp       int64    `json:"timestamp"`
+	ChallengeTokens []string `json:"challenge_tokens"`
 }
 
 type About struct {
@@ -459,6 +460,15 @@ func (s *SignalClient) send(number string, message string,
 			if strings.Contains(err.Error(), signalCliV2GroupError) {
 				return nil, errors.New("Cannot send message to group - please first update your profile.")
 			}
+
+			switch errorType := err.(type) {
+			case *RateLimitErrorType:
+				rateLimitError := errors.New(err.Error() + ". Use the attached challenge tokens to lift the rate limit restrictions via the '/v1/accounts/{number}/rate-limit-challenge' endpoint.")
+				resp.ChallengeTokens = errorType.ChallengeTokens
+				return &resp, rateLimitError
+			default:
+				return nil, err
+			}
 			return nil, err
 		}
 	} else {
diff --git a/src/client/jsonrpc2.go b/src/client/jsonrpc2.go
index c04c8c31..08a30009 100644
--- a/src/client/jsonrpc2.go
+++ b/src/client/jsonrpc2.go
@@ -7,7 +7,6 @@ import (
 	"net"
 	"time"
 	"sync"
-	"strings"
 
 	"github.com/bbernhard/signal-cli-rest-api/utils"
 	uuid "github.com/gofrs/uuid"
@@ -45,6 +44,15 @@ type RateLimitResult struct {
 	Token string `json:"token"`
 }
 
+type RateLimitErrorType struct {
+	ChallengeTokens []string
+	Err             error
+}
+
+func (r *RateLimitErrorType) Error() string {
+	return r.Err.Error()
+}
+
 type JsonRpc2Client struct {
 	conn                     net.Conn
 	receivedResponsesById    map[string]chan JsonRpc2MessageResponse
@@ -151,7 +159,10 @@ func (r *JsonRpc2Client) getRaw(command string, account *string, args interface{
 				challengeTokens = append(challengeTokens, rateLimitResult.Token)
 			}
 
-			return "", errors.New(resp.Err.Message + " Challenge Tokens: " + strings.Join(challengeTokens, ","))
+			return "", &RateLimitErrorType{
+							ChallengeTokens: challengeTokens,
+							Err : errors.New(resp.Err.Message),
+						}
 		}
 		return "", errors.New(resp.Err.Message)
 	}
diff --git a/src/docs/docs.go b/src/docs/docs.go
index e982b40a..23652480 100644
--- a/src/docs/docs.go
+++ b/src/docs/docs.go
@@ -1905,7 +1905,7 @@ var doc = `{
                     "400": {
                         "description": "Bad Request",
                         "schema": {
-                            "$ref": "#/definitions/api.Error"
+                            "$ref": "#/definitions/api.SendMessageError"
                         }
                     }
                 }
@@ -2089,6 +2089,20 @@ var doc = `{
                 }
             }
         },
+        "api.SendMessageError": {
+            "type": "object",
+            "properties": {
+                "challenge_tokens": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
+                "error": {
+                    "type": "string"
+                }
+            }
+        },
         "api.SendMessageResponse": {
             "type": "object",
             "properties": {
diff --git a/src/docs/swagger.json b/src/docs/swagger.json
index 98d9c139..45cf5dae 100644
--- a/src/docs/swagger.json
+++ b/src/docs/swagger.json
@@ -1889,7 +1889,7 @@
                     "400": {
                         "description": "Bad Request",
                         "schema": {
-                            "$ref": "#/definitions/api.Error"
+                            "$ref": "#/definitions/api.SendMessageError"
                         }
                     }
                 }
@@ -2073,6 +2073,20 @@
                 }
             }
         },
+        "api.SendMessageError": {
+            "type": "object",
+            "properties": {
+                "challenge_tokens": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
+                "error": {
+                    "type": "string"
+                }
+            }
+        },
         "api.SendMessageResponse": {
             "type": "object",
             "properties": {
diff --git a/src/docs/swagger.yaml b/src/docs/swagger.yaml
index e26fdde9..3b0a4f6a 100644
--- a/src/docs/swagger.yaml
+++ b/src/docs/swagger.yaml
@@ -116,6 +116,15 @@ definitions:
       registered:
         type: boolean
     type: object
+  api.SendMessageError:
+    properties:
+      challenge_tokens:
+        items:
+          type: string
+        type: array
+      error:
+        type: string
+    type: object
   api.SendMessageResponse:
     properties:
       timestamp:
@@ -1598,7 +1607,7 @@ paths:
         "400":
           description: Bad Request
           schema:
-            $ref: '#/definitions/api.Error'
+            $ref: '#/definitions/api.SendMessageError'
       summary: Send a signal message.
       tags:
       - Messages