diff --git a/backend/src/api/bitcoin/bitcoin.routes.ts b/backend/src/api/bitcoin/bitcoin.routes.ts
index 3b33c1ead..d2d298e09 100644
--- a/backend/src/api/bitcoin/bitcoin.routes.ts
+++ b/backend/src/api/bitcoin/bitcoin.routes.ts
@@ -42,6 +42,7 @@ class BitcoinRoutes {
       .get(config.MEMPOOL.API_URL_PREFIX + 'blocks/:height', this.getBlocks.bind(this))
       .get(config.MEMPOOL.API_URL_PREFIX + 'block/:hash', this.getBlock)
       .get(config.MEMPOOL.API_URL_PREFIX + 'block/:hash/summary', this.getStrippedBlockTransactions)
+      .get(config.MEMPOOL.API_URL_PREFIX + 'block/:hash/tx/:txid/summary', this.getStrippedBlockTransaction)
       .get(config.MEMPOOL.API_URL_PREFIX + 'block/:hash/audit-summary', this.getBlockAuditSummary)
       .get(config.MEMPOOL.API_URL_PREFIX + 'block/:hash/tx/:txid/audit', this.$getBlockTxAuditSummary)
       .get(config.MEMPOOL.API_URL_PREFIX + 'blocks/tip/height', this.getBlockTipHeight)
@@ -321,6 +322,20 @@ class BitcoinRoutes {
     }
   }
 
+  private async getStrippedBlockTransaction(req: Request, res: Response) {
+    try {
+      const transaction = await blocks.$getSingleTxFromSummary(req.params.hash, req.params.txid);
+      if (!transaction) {
+        handleError(req, res, 404, `transaction not found in summary`);
+        return;
+      }
+      res.setHeader('Expires', new Date(Date.now() + 1000 * 3600 * 24 * 30).toUTCString());
+      res.json(transaction);
+    } catch (e) {
+      res.status(500).send(e instanceof Error ? e.message : e);
+    }
+  }
+
   private async getBlock(req: Request, res: Response) {
     try {
       const block = await blocks.$getBlock(req.params.hash);
diff --git a/backend/src/api/blocks.ts b/backend/src/api/blocks.ts
index 3420d99c8..e621056ab 100644
--- a/backend/src/api/blocks.ts
+++ b/backend/src/api/blocks.ts
@@ -1224,6 +1224,11 @@ class Blocks {
     return summary.transactions;
   }
 
+  public async $getSingleTxFromSummary(hash: string, txid: string): Promise<TransactionClassified | null> {
+    const txs = await this.$getStrippedBlockTransactions(hash);
+    return txs.find(tx => tx.txid === txid) || null;
+  }
+
   /**
    * Get 15 blocks
    * 
diff --git a/frontend/src/app/components/transaction/transaction.component.ts b/frontend/src/app/components/transaction/transaction.component.ts
index 5f5ef4fa7..f19a5bcbd 100644
--- a/frontend/src/app/components/transaction/transaction.component.ts
+++ b/frontend/src/app/components/transaction/transaction.component.ts
@@ -406,6 +406,30 @@ export class TransactionComponent implements OnInit, AfterViewInit, OnDestroy {
         const auditAvailable = this.isAuditAvailable(height);
         const isCoinbase = this.tx.vin.some(v => v.is_coinbase);
         const fetchAudit = auditAvailable && !isCoinbase;
+
+        const addFirstSeen = (audit: TxAuditStatus | null, hash: string, height: number, txid: string, useFullSummary: boolean) => {
+          if (
+            this.isFirstSeenAvailable(height)
+            && !audit?.firstSeen             // firstSeen is not already in audit
+            && (!audit || audit?.seen)       // audit is disabled or tx is already seen (meaning 'firstSeen' is in block summary)
+          ) {
+            return useFullSummary ?
+              this.apiService.getStrippedBlockTransactions$(hash).pipe(
+                map(strippedTxs => {
+                  return { audit, firstSeen: strippedTxs.find(tx => tx.txid === txid)?.time };
+                }),
+                catchError(() => of({ audit }))
+              ) :
+              this.apiService.getStrippedBlockTransaction$(hash, txid).pipe(
+                map(strippedTx => {
+                  return { audit, firstSeen: strippedTx?.time };
+                }),
+                catchError(() => of({ audit }))
+              );
+          }
+          return of({ audit });
+        };
+
         if (fetchAudit) {
         // If block audit is already cached, use it to get transaction audit
           const blockAuditLoaded = this.apiService.getBlockAuditLoaded(hash);
@@ -428,24 +452,31 @@ export class TransactionComponent implements OnInit, AfterViewInit, OnDestroy {
                   accelerated: isAccelerated,
                   firstSeen,
                 };
+              }),
+              switchMap(audit => addFirstSeen(audit, hash, height, txid, true)),
+              catchError(() => {
+                return of({ audit: null });
               })
             )
           } else {
             return this.apiService.getBlockTxAudit$(hash, txid).pipe(
               retry({ count: 3, delay: 2000 }),
+              switchMap(audit => addFirstSeen(audit, hash, height, txid, false)),
               catchError(() => {
-                return of(null);
+                return of({ audit: null });
               })
             )
           }
         } else {
-          return of(isCoinbase ? { coinbase: true } : null);
+          const audit = isCoinbase ? { coinbase: true } : null;
+          return addFirstSeen(audit, hash, height, txid, this.apiService.getBlockSummaryLoaded(hash));
         }
       }),
     ).subscribe(auditStatus => {
-      this.auditStatus = auditStatus;
-      if (this.auditStatus?.firstSeen) {
-        this.transactionTime = this.auditStatus.firstSeen;
+      this.auditStatus = auditStatus?.audit;
+      const firstSeen = this.auditStatus?.firstSeen || auditStatus['firstSeen'];
+      if (firstSeen) {
+        this.transactionTime = firstSeen;
       }
       this.setIsAccelerated();
     });
@@ -922,6 +953,11 @@ export class TransactionComponent implements OnInit, AfterViewInit, OnDestroy {
           return false;
         }
         break;
+      case 'testnet4':
+        if (blockHeight < this.stateService.env.TESTNET4_BLOCK_AUDIT_START_HEIGHT) {
+          return false;
+        }
+        break;
       case 'signet':
         if (blockHeight < this.stateService.env.SIGNET_BLOCK_AUDIT_START_HEIGHT) {
           return false;
@@ -935,6 +971,34 @@ export class TransactionComponent implements OnInit, AfterViewInit, OnDestroy {
     return true;
   }
 
+  isFirstSeenAvailable(blockHeight: number): boolean {
+    if (this.stateService.env.BASE_MODULE !== 'mempool') {
+      return false;
+    }
+    switch (this.stateService.network) {
+      case 'testnet':
+        if (this.stateService.env.TESTNET_TX_FIRST_SEEN_START_HEIGHT && blockHeight >= this.stateService.env.TESTNET_TX_FIRST_SEEN_START_HEIGHT) {
+          return true;
+        }
+        break;
+      case 'testnet4':
+        if (this.stateService.env.TESTNET4_TX_FIRST_SEEN_START_HEIGHT && blockHeight >= this.stateService.env.TESTNET4_TX_FIRST_SEEN_START_HEIGHT) {
+          return true;
+        }
+        break;
+      case 'signet':
+        if (this.stateService.env.SIGNET_TX_FIRST_SEEN_START_HEIGHT && blockHeight >= this.stateService.env.SIGNET_TX_FIRST_SEEN_START_HEIGHT) {
+          return true;
+        }
+        break;
+      default:
+        if (this.stateService.env.MAINNET_TX_FIRST_SEEN_START_HEIGHT && blockHeight >= this.stateService.env.MAINNET_TX_FIRST_SEEN_START_HEIGHT) {
+          return true;
+        }
+    }
+    return false;
+  }
+
   resetTransaction() {
     this.firstLoad = false;
     this.gotInitialPosition = false;
diff --git a/frontend/src/app/services/api.service.ts b/frontend/src/app/services/api.service.ts
index 08251ddae..3c8cf8807 100644
--- a/frontend/src/app/services/api.service.ts
+++ b/frontend/src/app/services/api.service.ts
@@ -18,6 +18,7 @@ export class ApiService {
   private apiBasePath: string; // network path is /testnet, etc. or '' for mainnet
 
   private requestCache = new Map<string, { subject: BehaviorSubject<any>, expiry: number }>;
+  public blockSummaryLoaded: { [hash: string]: boolean } = {};
   public blockAuditLoaded: { [hash: string]: boolean } = {};
 
   constructor(
@@ -318,9 +319,14 @@ export class ApiService {
   }
 
   getStrippedBlockTransactions$(hash: string): Observable<TransactionStripped[]> {
+    this.setBlockSummaryLoaded(hash);
     return this.httpClient.get<TransactionStripped[]>(this.apiBaseUrl + this.apiBasePath + '/api/v1/block/' + hash + '/summary');
   }
 
+  getStrippedBlockTransaction$(hash: string, txid: string): Observable<TransactionStripped> {
+    return this.httpClient.get<TransactionStripped>(this.apiBaseUrl + this.apiBasePath + '/api/v1/block/' + hash + '/tx/' + txid + '/summary');
+  }
+
   getDifficultyAdjustments$(interval: string | undefined): Observable<any> {
     return this.httpClient.get<any[]>(
         this.apiBaseUrl + this.apiBasePath + `/api/v1/mining/difficulty-adjustments` +
@@ -567,4 +573,12 @@ export class ApiService {
   getBlockAuditLoaded(hash) {
     return this.blockAuditLoaded[hash];
   }
+
+  async setBlockSummaryLoaded(hash: string) {
+    this.blockSummaryLoaded[hash] = true;
+  }
+
+  getBlockSummaryLoaded(hash) {
+    return this.blockSummaryLoaded[hash];
+  }
 }
diff --git a/frontend/src/app/services/state.service.ts b/frontend/src/app/services/state.service.ts
index 8dd17cf75..2feb266d1 100644
--- a/frontend/src/app/services/state.service.ts
+++ b/frontend/src/app/services/state.service.ts
@@ -68,7 +68,12 @@ export interface Env {
   AUDIT: boolean;
   MAINNET_BLOCK_AUDIT_START_HEIGHT: number;
   TESTNET_BLOCK_AUDIT_START_HEIGHT: number;
+  TESTNET4_BLOCK_AUDIT_START_HEIGHT: number;
   SIGNET_BLOCK_AUDIT_START_HEIGHT: number;
+  MAINNET_TX_FIRST_SEEN_START_HEIGHT: number;
+  TESTNET_TX_FIRST_SEEN_START_HEIGHT: number;
+  TESTNET4_TX_FIRST_SEEN_START_HEIGHT: number;
+  SIGNET_TX_FIRST_SEEN_START_HEIGHT: number;
   HISTORICAL_PRICE: boolean;
   ACCELERATOR: boolean;
   ACCELERATOR_BUTTON: boolean;
@@ -107,7 +112,12 @@ const defaultEnv: Env = {
   'AUDIT': false,
   'MAINNET_BLOCK_AUDIT_START_HEIGHT': 0,
   'TESTNET_BLOCK_AUDIT_START_HEIGHT': 0,
+  'TESTNET4_BLOCK_AUDIT_START_HEIGHT': 0,
   'SIGNET_BLOCK_AUDIT_START_HEIGHT': 0,
+  'MAINNET_TX_FIRST_SEEN_START_HEIGHT': 0,
+  'TESTNET_TX_FIRST_SEEN_START_HEIGHT': 0,
+  'TESTNET4_TX_FIRST_SEEN_START_HEIGHT': 0,
+  'SIGNET_TX_FIRST_SEEN_START_HEIGHT': 0,
   'HISTORICAL_PRICE': true,
   'ACCELERATOR': false,
   'ACCELERATOR_BUTTON': true,
diff --git a/production/mempool-frontend-config.mainnet.json b/production/mempool-frontend-config.mainnet.json
index 61a8c2c2a..79acaecc5 100644
--- a/production/mempool-frontend-config.mainnet.json
+++ b/production/mempool-frontend-config.mainnet.json
@@ -13,6 +13,7 @@
   "MAINNET_BLOCK_AUDIT_START_HEIGHT": 773911,
   "TESTNET_BLOCK_AUDIT_START_HEIGHT": 2417829,
   "SIGNET_BLOCK_AUDIT_START_HEIGHT": 127609,
+  "MAINNET_TX_FIRST_SEEN_START_HEIGHT": 838316,
   "ITEMS_PER_PAGE": 25,
   "LIGHTNING": true,
   "ACCELERATOR": true,