diff --git a/src/clients/mdw-http-client.model.ts b/src/clients/mdw-http-client.model.ts
index 95398cc4..ee7ba673 100644
--- a/src/clients/mdw-http-client.model.ts
+++ b/src/clients/mdw-http-client.model.ts
@@ -81,9 +81,20 @@ export type TransactionWithContext = {
   micro_index: string;
   micro_time: string;
   signatures: string[];
-  tx: Transaction;
+  tx: Transaction | PayingForTx;
 };
 
+export type PayingForTx = {
+  type: PayingForTxType;
+  tx: {
+    tx: Transaction;
+  };
+};
+
+export enum PayingForTxType {
+  PayingForTx = 'PayingForTx',
+}
+
 export type Transaction = {
   abi_version: string;
   aexn_type: string | null;
diff --git a/src/clients/mdw-http-client.service.ts b/src/clients/mdw-http-client.service.ts
index 0951a8b4..831f1ba5 100644
--- a/src/clients/mdw-http-client.service.ts
+++ b/src/clients/mdw-http-client.service.ts
@@ -8,6 +8,9 @@ import {
   ContractLog,
   MdwMicroBlock,
   MdwPaginatedResponse,
+  PayingForTx,
+  PayingForTxType,
+  Transaction,
   TransactionWithContext,
 } from '@/clients/mdw-http-client.model';
 import {
@@ -91,7 +94,10 @@ export class MdwHttpClientService {
   async getSenderAccountForTransaction(txHash: TxHash): Promise<string> {
     if (!this.transactionSenderMapping.has(txHash)) {
       const tx = await this.getTransaction(txHash);
-      this.transactionSenderMapping.set(txHash, tx.tx.caller_id);
+      this.transactionSenderMapping.set(
+        txHash,
+        this.getSenderFromTransaction(tx),
+      );
     }
     return this.transactionSenderMapping.get(txHash)!;
   }
@@ -105,7 +111,10 @@ export class MdwHttpClientService {
       `/v3/transactions?contract_id=${process.env.ROUTER_ADDRESS}&${this.defaultParams}`,
     );
     transactions.forEach((tx) => {
-      this.transactionSenderMapping.set(tx.hash, tx.tx.caller_id);
+      this.transactionSenderMapping.set(
+        tx.hash,
+        this.getSenderFromTransaction(tx),
+      );
     });
   }
 
@@ -140,4 +149,14 @@ export class MdwHttpClientService {
 
     return result.data;
   }
+
+  private getSenderFromTransaction(
+    transactionWithContext: TransactionWithContext,
+  ): string {
+    if (transactionWithContext.tx.type === PayingForTxType.PayingForTx) {
+      return (transactionWithContext.tx as PayingForTx).tx.tx.caller_id;
+    } else {
+      return (transactionWithContext.tx as Transaction).caller_id;
+    }
+  }
 }