diff --git a/mobile/constants/i18n/index.ts b/mobile/constants/i18n/index.ts
index 4df1245..ce52231 100644
--- a/mobile/constants/i18n/index.ts
+++ b/mobile/constants/i18n/index.ts
@@ -6,6 +6,7 @@ import { initReactI18next } from 'react-i18next';
 
 import ar from '../../locales/ar.json';
 import en from '../../locales/en.json';
+import es from '../../locales/es.json';
 import fr from '../../locales/fr.json';
 import sw from '../../locales/sw.json';
 
@@ -13,7 +14,7 @@ export type SupportedLanguage = 'ar' | 'en' | 'es' | 'fr' | 'sw';
 export const LANGUAGE_STORAGE_KEY = 'esustellar_app_language';
 
 /** Languages written right-to-left. */
-const RTL_LANGUAGES: ReadonlySet<SupportedLanguage> = new Set(['ar']);
+const RTL_LANGUAGES: ReadonlySet<SupportedLanguage> = new Set<SupportedLanguage>(['ar']);
 
 export const languageOptions = [
   { label: 'العربية', value: 'ar' as SupportedLanguage },
@@ -33,110 +34,7 @@ const applyRTL = (lang: SupportedLanguage): void => {
 const resources = {
   ar: { translation: ar },
   en: { translation: en },
-  es: {
-    translation: {
-      tabs: {
-        home: 'Inicio',
-        groups: 'Grupos',
-        notifications: 'Notificaciones',
-        profile: 'Perfil',
-      },
-      home: {
-        goodMorning: 'Buenos días',
-        goodAfternoon: 'Buenas tardes',
-        goodEvening: 'Buenas noches',
-        defaultUser: 'Usuario de EsuStellar',
-        totalBalance: 'Saldo total',
-        quickActions: 'Accesos rápidos',
-        balanceValue: '— XLM',
-        notifications: 'Notificaciones',
-      },
-      onboarding: {
-        skip: 'Omitir',
-        next: 'Siguiente',
-        getStarted: 'Comenzar',
-        stayInformed: 'Mantente informado',
-        notificationBody:
-          'Recibe recordatorios de fechas de vencimiento, pagos y actualizaciones del grupo para no perderte ningún momento importante.',
-        allowNotifications: 'Permitir notificaciones',
-        skipForNow: 'Omitir por ahora',
-        slides: {
-          welcome: {
-            eyebrow: 'Bienvenido',
-            title: 'Ahorra con personas de confianza',
-            description:
-              'Lleva tu círculo de ahorro comunitario a la cadena de bloques sin perder la experiencia familiar de grupo.',
-          },
-          transparent: {
-            eyebrow: 'Transparente',
-            title: 'Sigue cada contribución claramente',
-            description:
-              'Mantente al tanto de los pagos, fechas de vencimiento y el progreso del grupo con actualizaciones simples en un solo lugar.',
-          },
-          secure: {
-            eyebrow: 'Seguro',
-            title: 'Comienza con confianza',
-            description:
-              'Conecta tu billetera Stellar, gestiona tus opciones de seguridad y recibe recordatorios útiles cuando importa.',
-          },
-        },
-      },
-      settings: {
-        title: 'Ajustes de seguridad',
-        walletAddress: 'Dirección de la billetera',
-        copyWalletAddress: 'Copiar dirección de la billetera',
-        copyToast: 'Dirección copiada al portapapeles',
-        copyFailed: 'No se pudo copiar la dirección',
-        biometricAuthentication: 'Autenticación biométrica',
-        supported: 'Compatible',
-        enableBiometrics: 'Activar biometría',
-        useToSignIn: 'Usa {{supportedLabel}} para iniciar sesión',
-        checkingDeviceCapabilities: 'Comprobando capacidades del dispositivo…',
-        biometricsNotSupported: 'La biometría no es compatible con este dispositivo',
-        setUpPinFallback:
-          'Configura un PIN como respaldo cuando la biometría no esté disponible.',
-        noBiometricsEnrolled: 'No hay biometría registrada',
-        setupBiometricsHelper:
-          'Configura huella o reconocimiento facial en los ajustes del dispositivo y vuelve aquí para activarlo.',
-        about: 'Acerca de',
-        version: 'Versión',
-        build: 'Compilación',
-        pinFallback: 'PIN de respaldo',
-        pinDescription:
-          'Configura un PIN de 4-6 dígitos como respaldo cuando la biometría no esté disponible.',
-        setUpPin: 'Configurar PIN',
-        enterPin: 'Ingresa tu PIN',
-        confirmYourPin: 'Confirma tu PIN',
-        pinDigits: '4-6 dígitos',
-        reenterPin: 'Vuelve a ingresar el PIN',
-        cancel: 'Cancelar',
-        next: 'Siguiente',
-        confirm: 'Confirmar',
-        pinSet: 'El PIN está configurado',
-        pinFallbackInfo: 'Se usa como respaldo cuando la biometría falla',
-        change: 'Cambiar',
-        remove: 'Eliminar',
-        pinMustDigits: 'El PIN debe tener 4-6 dígitos',
-        pinsDoNotMatch: 'Los PIN no coinciden',
-        biometricsEnabled: 'Autenticación biométrica activada',
-        biometricsDisabled: 'Autenticación biométrica desactivada',
-        biometricFailed: 'La verificación biométrica falló',
-        failedToSavePin: 'No se pudo guardar el PIN',
-        pinRemoved: 'PIN eliminado',
-        language: 'Idioma',
-        languageLabel: 'Elige el idioma de la aplicación',
-        languageChangeSuccess: 'Idioma actualizado.',
-      },
-      profile: {
-        editProfile: 'Editar perfil',
-        settings: 'Ajustes',
-        disconnectWallet: 'Desconectar billetera',
-      },
-      lock: {
-        tapToUnlock: 'Toca para desbloquear',
-      },
-    },
-  },
+  es: { translation: es },
   fr: { translation: fr },
   sw: { translation: sw },
 };
diff --git a/mobile/locales/es.json b/mobile/locales/es.json
new file mode 100644
index 0000000..dc932bc
--- /dev/null
+++ b/mobile/locales/es.json
@@ -0,0 +1,95 @@
+{
+  "tabs": {
+    "home": "Inicio",
+    "groups": "Grupos",
+    "notifications": "Notificaciones",
+    "profile": "Perfil"
+  },
+  "home": {
+    "goodMorning": "Buenos días",
+    "goodAfternoon": "Buenas tardes",
+    "goodEvening": "Buenas noches",
+    "defaultUser": "Usuario de EsuStellar",
+    "totalBalance": "Saldo total",
+    "quickActions": "Accesos rápidos",
+    "balanceValue": "— XLM",
+    "notifications": "Notificaciones"
+  },
+  "onboarding": {
+    "skip": "Omitir",
+    "next": "Siguiente",
+    "getStarted": "Comenzar",
+    "stayInformed": "Mantente informado",
+    "notificationBody": "Recibe recordatorios de fechas de vencimiento, pagos y actualizaciones del grupo para no perderte ningún momento importante.",
+    "allowNotifications": "Permitir notificaciones",
+    "skipForNow": "Omitir por ahora",
+    "slides": {
+      "welcome": {
+        "eyebrow": "Bienvenido",
+        "title": "Ahorra con personas de confianza",
+        "description": "Lleva tu círculo de ahorro comunitario a la cadena de bloques sin perder la experiencia familiar de grupo."
+      },
+      "transparent": {
+        "eyebrow": "Transparente",
+        "title": "Sigue cada contribución claramente",
+        "description": "Mantente al tanto de los pagos, fechas de vencimiento y el progreso del grupo con actualizaciones simples en un solo lugar."
+      },
+      "secure": {
+        "eyebrow": "Seguro",
+        "title": "Comienza con confianza",
+        "description": "Conecta tu billetera Stellar, gestiona tus opciones de seguridad y recibe recordatorios útiles cuando importa."
+      }
+    }
+  },
+  "settings": {
+    "title": "Ajustes de seguridad",
+    "walletAddress": "Dirección de la billetera",
+    "copyWalletAddress": "Copiar dirección de la billetera",
+    "copyToast": "Dirección copiada al portapapeles",
+    "copyFailed": "No se pudo copiar la dirección",
+    "biometricAuthentication": "Autenticación biométrica",
+    "supported": "Compatible",
+    "enableBiometrics": "Activar biometría",
+    "useToSignIn": "Usa {{supportedLabel}} para iniciar sesión",
+    "checkingDeviceCapabilities": "Comprobando capacidades del dispositivo…",
+    "biometricsNotSupported": "La biometría no es compatible con este dispositivo",
+    "setUpPinFallback": "Configura un PIN como respaldo cuando la biometría no esté disponible.",
+    "noBiometricsEnrolled": "No hay biometría registrada",
+    "setupBiometricsHelper": "Configura huella o reconocimiento facial en los ajustes del dispositivo y vuelve aquí para activarlo.",
+    "about": "Acerca de",
+    "version": "Versión",
+    "build": "Compilación",
+    "pinFallback": "PIN de respaldo",
+    "pinDescription": "Configura un PIN de 4-6 dígitos como respaldo cuando la biometría no esté disponible.",
+    "setUpPin": "Configurar PIN",
+    "enterPin": "Ingresa tu PIN",
+    "confirmYourPin": "Confirma tu PIN",
+    "pinDigits": "4-6 dígitos",
+    "reenterPin": "Vuelve a ingresar el PIN",
+    "cancel": "Cancelar",
+    "next": "Siguiente",
+    "confirm": "Confirmar",
+    "pinSet": "El PIN está configurado",
+    "pinFallbackInfo": "Se usa como respaldo cuando la biometría falla",
+    "change": "Cambiar",
+    "remove": "Eliminar",
+    "pinMustDigits": "El PIN debe tener 4-6 dígitos",
+    "pinsDoNotMatch": "Los PIN no coinciden",
+    "biometricsEnabled": "Autenticación biométrica activada",
+    "biometricsDisabled": "Autenticación biométrica desactivada",
+    "biometricFailed": "La verificación biométrica falló",
+    "failedToSavePin": "No se pudo guardar el PIN",
+    "pinRemoved": "PIN eliminado",
+    "language": "Idioma",
+    "languageLabel": "Elige el idioma de la aplicación",
+    "languageChangeSuccess": "Idioma actualizado."
+  },
+  "profile": {
+    "editProfile": "Editar perfil",
+    "settings": "Ajustes",
+    "disconnectWallet": "Desconectar billetera"
+  },
+  "lock": {
+    "tapToUnlock": "Toca para desbloquear"
+  }
+}
\ No newline at end of file
diff --git a/mobile/services/api/transactionsApi.ts b/mobile/services/api/transactionsApi.ts
index 7b82b03..6c21d64 100644
--- a/mobile/services/api/transactionsApi.ts
+++ b/mobile/services/api/transactionsApi.ts
@@ -24,9 +24,13 @@ class TransactionsApiService {
   }
 
   /**
-   * Get all transactions for a user
+   * Get all transactions for a user (paginated)
    */
-  async getUserTransactions(userAddress: string): Promise<ApiResponse<Transaction[]>> {
+  async getUserTransactions(
+    userAddress: string,
+    cursor?: string,
+    limit: number = 20
+  ): Promise<ApiResponse<Transaction[]>> {
     try {
       console.log(`Fetching transactions for user: ${userAddress}`);
 
@@ -68,6 +72,59 @@ class TransactionsApiService {
       };
     }
   }
+
+  /**
+   * Get paginated transactions with cursor
+   */
+  async getPaginatedTransactions(
+    userAddress: string,
+    cursor?: string,
+    limit: number = 20
+  ): Promise<ApiResponse<{
+    transactions: Transaction[];
+    hasMore: boolean;
+    nextCursor?: string;
+    totalCount: number;
+  }>> {
+    try {
+      console.log(`Fetching paginated transactions for user: ${userAddress}`);
+
+      await new Promise(resolve => setTimeout(resolve, 800));
+
+      const totalMockEntities = 50;
+      const allMockTx: Transaction[] = Array.from({ length: totalMockEntities }, (_, i) => ({
+        id: `tx_${i + 1}`,
+        groupId: `group_${(i % 3) + 1}`,
+        userAddress,
+        amount: (i + 1) * 100,
+        type: i % 2 === 0 ? 'contribution' : 'payout',
+        status: 'confirmed',
+        createdAt: new Date(Date.now() - i * 3600000).toISOString(),
+        txHash: `0xhash${i}${Date.now().toString(16)}`,
+      }));
+
+      const pageIndex = cursor ? parseInt(cursor, 10) : 0;
+      const startIndex = pageIndex * limit;
+      const endIndex = Math.min(startIndex + limit, allMockTx.length);
+      const pageTx = allMockTx.slice(startIndex, endIndex);
+
+      return {
+        success: true,
+        data: {
+          transactions: pageTx,
+          hasMore: endIndex < allMockTx.length,
+          nextCursor: endIndex < allMockTx.length ? String(pageIndex + 1) : undefined,
+          totalCount: allMockTx.length,
+        },
+      };
+    } catch (error) {
+      console.error('Failed to fetch paginated transactions:', error);
+      return {
+        success: false,
+        error: 'Failed to fetch paginated transactions',
+      };
+    }
+  }
 }
 
 export const transactionsApi = new TransactionsApiService();
diff --git a/mobile/services/queryClient.ts b/mobile/services/queryClient.ts
index 12925e1..7698d28 100644
--- a/mobile/services/queryClient.ts
+++ b/mobile/services/queryClient.ts
@@ -28,6 +28,7 @@ export const queryKeys = {
   },
   transactions: {
     all: ['transactions'] as const,
+    user: (address: string) => ['transactions', 'user', address] as const,
     group: (groupId: string) => ['transactions', groupId] as const,
   },
   notifications: {
diff --git a/mobile/services/sync/backgroundSync.ts b/mobile/services/sync/backgroundSync.ts
index 91f5414..c7c8817 100644
--- a/mobile/services/sync/backgroundSync.ts
+++ b/mobile/services/sync/backgroundSync.ts
@@ -130,11 +130,23 @@ class BackgroundSyncService {
    * Sync transactions data
    */
   private async syncTransactions(userAddress: string) {
-    const result = await transactionsApi.getUserTransactions(userAddress);
-    if (result.success && result.data) {
-      queryClient.setQueryData(['transactions', 'user', userAddress], result);
-      console.log('[SyncService] Transactions synced successfully');
+    const result = await transactionSyncService.syncTransactions(userAddress);
+    
+    if (!result.success) {
+      console.error('[SyncService] Transaction sync failed:', result.error);
+      return;
     }
+
+    const existingData = queryClient.getQueryData<{ data?: Transaction[] }>(
+      queryKeys.transactions.user(userAddress)
+    );
+    
+    queryClient.setQueryData(
+      queryKeys.transactions.user(userAddress),
+      { ...existingData, data: existingData?.data || [] }
+    );
+    
+    console.log('[SyncService] Transactions synced successfully');
   }
 
   /**
diff --git a/mobile/services/sync/transactions.ts b/mobile/services/sync/transactions.ts
new file mode 100644
index 0000000..677ed43
--- /dev/null
+++ b/mobile/services/sync/transactions.ts
@@ -0,0 +1,244 @@
+import { queryClient, queryKeys } from '../queryClient';
+import { transactionsApi, Transaction } from '../api/transactionsApi';
+
+export interface TransactionPage {
+  transactions: Transaction[];
+  hasMore: boolean;
+  nextCursor?: string;
+  totalCount: number;
+}
+
+export interface SyncResult {
+  success: boolean;
+  error?: string;
+  syncedCount: number;
+  hasMore: boolean;
+}
+
+class TransactionSyncService {
+  private isSyncing: boolean = false;
+  private syncQueue: Promise<void> = Promise.resolve();
+
+  async syncTransactions(
+    userAddress: string,
+    options: {
+      cursor?: string;
+      limit?: number;
+      since?: string;
+    } = {}
+  ): Promise<SyncResult> {
+    const { cursor, limit = 20, since } = options;
+
+    if (this.isSyncing) {
+      return this.enqueueSync(userAddress, options);
+    }
+
+    this.isSyncing = true;
+    
+    try {
+      const result = await this.fetchTransactions(userAddress, { cursor, limit });
+      
+      if (!result.success) {
+        return { success: false, error: result.error, syncedCount: 0, hasMore: false };
+      }
+
+      await this.mergeTransactions(userAddress, result.data as TransactionPage, { since });
+      
+      return {
+        success: true,
+        syncedCount: (result.data as TransactionPage)?.transactions.length || 0,
+        hasMore: (result.data as TransactionPage)?.hasMore || false,
+      };
+    } catch (error) {
+      const errorMsg = error instanceof Error ? error.message : 'Failed to sync transactions';
+      console.error('[TransactionSync] Sync failed:', errorMsg);
+      return { success: false, error: errorMsg, syncedCount: 0, hasMore: false };
+    } finally {
+      this.isSyncing = false;
+    }
+  }
+
+  private enqueueSync(userAddress: string, options: Record<string, unknown>): Promise<SyncResult> {
+    const prevPromise = this.syncQueue;
+    let resolveSelf: (value: SyncResult) => void;
+    
+    this.syncQueue = new Promise((resolve) => {
+      resolveSelf = resolve;
+    });
+
+    return prevPromise.then(() => this.syncTransactions(userAddress, options))
+      .then((result) => {
+        resolveSelf!(result);
+        return result;
+      })
+      .catch((error) => {
+        resolveSelf!({ success: false, error: error.message, syncedCount: 0, hasMore: false });
+        return { success: false, error: error.message, syncedCount: 0, hasMore: false };
+      });
+  }
+
+  private async fetchTransactions(
+    userAddress: string,
+    params: { cursor?: string; limit?: number }
+  ): Promise<{ success: boolean; data?: TransactionPage; error?: string }> {
+    try {
+      const existingData = queryClient.getQueryData<{ data?: Transaction[] }>(
+        queryKeys.transactions.user(userAddress)
+      );
+
+      const mergedTx = existingData?.data || [];
+      const existingIds = new Set(mergedTx.map(tx => tx.id));
+      const existingTxMap = new Map(mergedTx.map(tx => [tx.id, tx]));
+
+      const pageCount = Math.ceil(mergedTx.length / (params.limit || 20));
+      let startIndex = 0;
+      
+      if (params.cursor) {
+        startIndex = (parseInt(params.cursor, 10) - 1) * (params.limit || 20);
+      }
+
+      const paginatedTx = mergedTx.slice(startIndex, startIndex + (params.limit || 20));
+
+      return {
+        success: true,
+        data: {
+          transactions: paginatedTx,
+          hasMore: startIndex + (params.limit || 20) < mergedTx.length,
+          nextCursor: startIndex + (params.limit || 20) < mergedTx.length 
+            ? String(pageCount + 1) 
+            : undefined,
+          totalCount: mergedTx.length,
+        },
+      };
+    } catch (error) {
+      const errorMsg = error instanceof Error ? error.message : 'Failed to fetch transactions';
+      return { success: false, error: errorMsg };
+    }
+  }
+
+  private async mergeTransactions(
+    userAddress: string,
+    page: TransactionPage,
+    options: { since?: string }
+  ): Promise<void> {
+    const existingData = queryClient.getQueryData<{ data?: Transaction[] }>(
+      queryKeys.transactions.user(userAddress)
+    );
+
+    const existingTx = existingData?.data || [];
+    const existingTxMap = new Map(existingTx.map(tx => [tx.id, tx]));
+    
+    for (const newTx of page.transactions) {
+      const existingTx = existingTxMap.get(newTx.id);
+      
+      if (!existingTx || this.isNewerThan(existingTx, newTx, options.since)) {
+        existingTxMap.set(newTx.id, newTx);
+      }
+    }
+
+    const merged = Array.from(existingTxMap.values()).sort(
+      (a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime()
+    );
+
+    queryClient.setQueryData(
+      queryKeys.transactions.user(userAddress),
+      { ...existingData, data: merged }
+    );
+
+    queryClient.setQueryData(
+      queryKeys.transactions.all,
+      { ...existingData, data: merged }
+    );
+  }
+
+  private isNewerThan(
+    existing: Transaction,
+    incoming: Transaction,
+    since?: string
+  ): boolean {
+    if (since) {
+      const sinceDate = new Date(since);
+      const incomingDate = new Date(incoming.createdAt);
+      return incomingDate > sinceDate;
+    }
+    
+    return existing.status !== incoming.status || 
+           existing.txHash !== incoming.txHash;
+  }
+
+  async fetchDeltaUpdates(
+    userAddress: string,
+    since: string
+  ): Promise<SyncResult> {
+    try {
+      const newTransactions: Transaction[] = [];
+      
+      for (let i = 0; i < 3; i++) {
+        newTransactions.push({
+          id: `delta_tx_${Date.now()}_${i}`,
+          groupId: `group_${i + 1}`,
+          userAddress,
+          amount: 50 * (i + 1),
+          type: i % 2 === 0 ? 'contribution' : 'payout',
+          status: 'confirmed',
+          createdAt: new Date(Date.now() - Math.random() * 86400000).toISOString(),
+          txHash: `0xdelta${i}${Date.now().toString(16)}`,
+        });
+      }
+
+      const existingData = queryClient.getQueryData<{ data?: Transaction[] }>(
+        queryKeys.transactions.user(userAddress)
+      );
+
+      const existingTx = existingData?.data || [];
+      const existingIds = new Set(existingTx.map(tx => tx.id));
+      
+      const merged = [...existingTx];
+      for (const newTx of newTransactions) {
+        if (!existingIds.has(newTx.id)) {
+          merged.push(newTx);
+          existingIds.add(newTx.id);
+        }
+      }
+
+      const sorted = merged.sort(
+        (a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime()
+      );
+
+      queryClient.setQueryData(
+        queryKeys.transactions.user(userAddress),
+        { ...existingData, data: sorted }
+      );
+
+      return {
+        success: true,
+        syncedCount: newTransactions.length,
+        hasMore: false,
+      };
+    } catch (error) {
+      const errorMsg = error instanceof Error ? error.message : 'Failed to fetch delta updates';
+      return { success: false, error: errorMsg, syncedCount: 0, hasMore: false };
+    }
+  }
+
+  getIsSyncing(): boolean {
+    return this.isSyncing;
+  }
+
+  resetSyncState(): void {
+    this.isSyncing = false;
+    this.syncQueue = Promise.resolve();
+  }
+}
+
+export const transactionSyncService = new TransactionSyncService();
+
+export function useTransactionSync() {
+  return {
+    syncTransactions: (userAddress: string, options?: Record<string, unknown>) =>
+      transactionSyncService.syncTransactions(userAddress, options),
+    fetchDeltaUpdates: (userAddress: string, since: string) =>
+      transactionSyncService.fetchDeltaUpdates(userAddress, since),
+    isSyncing: transactionSyncService.getIsSyncing(),
+  };
+}
\ No newline at end of file