diff --git a/src/modules/banking/bank-cards/application/bank-operations.service.ts b/src/modules/banking/bank-cards/application/bank-operations.service.ts
index 8ffeec3..e4bdfe0 100644
--- a/src/modules/banking/bank-cards/application/bank-operations.service.ts
+++ b/src/modules/banking/bank-cards/application/bank-operations.service.ts
@@ -4,7 +4,6 @@ import {
   BankCardOperation,
   Prisma,
 } from '../../../../../generated/prisma/client';
-import { PrismaService } from '../../../../prisma/prisma.service';
 import { FIRST_PAGE } from '../domain/bank-card-limits';
 import { BankOperationKind } from '../domain/bank-operation-kind';
 import {
@@ -32,15 +31,10 @@ import {
   periodBounds,
 } from './bank-card-input';
 
-const EXPECTED_UPDATED_ROWS = 1;
-
 type Tx = Prisma.TransactionClient;
 @Injectable()
 export class BankOperationsService {
-  constructor(
-    private readonly prisma: PrismaService,
-    private readonly repository: BankCardsRepository,
-  ) {}
+  constructor(private readonly repository: BankCardsRepository) {}
 
   private async operationView(
     tx: Tx,
@@ -52,51 +46,7 @@ export class BankOperationsService {
   private async pageViews(tx: Tx, rows: BankCardOperation[]) {
     const userId = rows[0]?.userId;
     if (!userId) return [];
-    const cardIds = new Set(
-      rows.flatMap((row) =>
-        [row.cardId, row.targetCardId].filter(
-          (id): id is string => id !== null,
-        ),
-      ),
-    );
-    const sourceIds = new Set(
-      rows.flatMap((row) => (row.originalExpenseId ? [row.originalExpenseId] : [])),
-    );
-    const [cards, sources] = await Promise.all([
-      tx.bankCard.findMany({ where: { userId, id: { in: [...cardIds] } } }),
-      tx.bankCardOperation.findMany({
-        where: { userId, id: { in: [...sourceIds] } },
-      }),
-    ]);
-    const categoryIds = new Set(
-      rows
-        .map(
-          (row) =>
-            sources.find((source) => source.id === row.originalExpenseId)
-              ?.categoryId ?? row.categoryId,
-        )
-        .filter((id): id is string => id !== null),
-    );
-    const expenseIds = new Set(
-      rows.flatMap((row) => {
-        const source = sources.find((item) => item.id === row.originalExpenseId);
-        return row.kind === BankOperationKind.Expense || source
-          ? [source?.id ?? row.id]
-          : [];
-      }),
-    );
-    const [categories, refunds] = await Promise.all([
-      tx.expenseCategory.findMany({
-        where: { userId, id: { in: [...categoryIds] } },
-      }),
-      tx.bankCardOperation.findMany({
-        where: {
-          userId,
-          originalExpenseId: { in: [...expenseIds] },
-          deletedAt: null,
-        },
-      }),
-    ]);
+    const { cards, sources, categories, refunds } = await this.repository.operationViewData(tx, userId, rows);
     const cardsById = new Map(cards.map((card) => [card.id, card]));
     const sourcesById = new Map(sources.map((source) => [source.id, source]));
     const categoriesById = new Map(categories.map((category) => [category.id, category]));
@@ -172,16 +122,12 @@ export class BankOperationsService {
     if (operationFieldConflict(input)) fail();
     if (input.kind === BankOperationKind.Expense) {
       if (!input.categoryId) {
-        const category = await tx.expenseCategory.findUnique({
-          where: { userId_seedKey: { userId, seedKey: 'other' } },
-        });
+        const category = await this.repository.defaultCategory(tx, userId);
         if (!category) missing();
         input.categoryId = category.id;
       }
       if (
-        !(await tx.expenseCategory.findFirst({
-          where: { userId, id: input.categoryId },
-        }))
+        !(await this.repository.category(tx, userId, input.categoryId))
       ) {
         missing();
       }
@@ -199,29 +145,11 @@ export class BankOperationsService {
       ) {
         fail(BankErrorCode.InvalidRefund);
       }
-      if (
-        (
-          await tx.bankCardOperation.updateMany({
-            where: {
-              id: source.id,
-              userId,
-              version: source.version,
-              deletedAt: null,
-            },
-            data: { version: { increment: 1 } },
-          })
-        ).count !== EXPECTED_UPDATED_ROWS
-      ) {
-        conflict();
-      }
-      const refunds = await tx.bankCardOperation.findMany({
-        where: {
-          userId,
-          originalExpenseId: source.id,
-          deletedAt: null,
-          ...(old ? { id: { not: old.id } } : {}),
-        },
-      });
+      await this.repository.updateOperation(tx,
+        { id: source.id, userId, version: source.version, deletedAt: null },
+        { version: { increment: 1 } },
+      );
+      const refunds = await this.repository.refunds(tx, userId, source.id, old?.id);
       if (input.date < source.date) fail(BankErrorCode.InvalidDate);
       if (
         refunds.reduce((sum, r) => sum + r.amountKopecks, ZERO_KOPECKS) +
@@ -232,9 +160,7 @@ export class BankOperationsService {
       }
     }
     if (old?.kind === BankOperationKind.Expense) {
-      const refunds = await tx.bankCardOperation.findMany({
-        where: { userId, originalExpenseId: old.id, deletedAt: null },
-      });
+      const refunds = await this.repository.refunds(tx, userId, old.id);
       if (
         refunds.length &&
         (input.cardId !== old.cardId ||
@@ -251,9 +177,7 @@ export class BankOperationsService {
     const normalized = operationInput(dto),
       hash = fingerprint(normalized);
     return this.repository.write(async (tx) => {
-      const existing = await tx.bankCardOperation.findUnique({
-        where: { id: dto.id },
-      });
+      const existing = await this.repository.operationById(tx, dto.id);
       if (existing) {
         if (existing.userId !== userId) missing();
         // eslint-disable-next-line security/detect-possible-timing-attacks -- This compares an idempotency fingerprint after ownership validation, not a secret.
@@ -269,15 +193,15 @@ export class BankOperationsService {
       await this.validateOperation(tx, userId, input);
       return this.operationView(
         tx,
-        await tx.bankCardOperation.create({
-          data: { ...input, id: dto.id, userId, createFingerprint: hash },
+        await this.repository.createOperation(tx, {
+          ...input, id: dto.id, userId, createFingerprint: hash,
         }),
       );
     });
   }
 
   getOperation(userId: string, id: string) {
-    return this.prisma.$transaction(async (tx) => {
+    return this.repository.read(async (tx) => {
       const row = await this.repository.operation(tx, userId, id);
       if (row.deletedAt) missing();
       return this.operationView(tx, row);
@@ -302,16 +226,10 @@ export class BankOperationsService {
         description: dto.description ?? old.description ?? undefined,
       });
       await this.validateOperation(tx, userId, input, old);
-      if (
-        (
-          await tx.bankCardOperation.updateMany({
-            where: { id, userId, version: dto.version, deletedAt: null },
-            data: { ...input, version: { increment: 1 } },
-          })
-        ).count !== EXPECTED_UPDATED_ROWS
-      ) {
-        conflict();
-      }
+      await this.repository.updateOperation(tx,
+        { id, userId, version: dto.version, deletedAt: null },
+        { ...input, version: { increment: 1 } },
+      );
       return this.operationView(
         tx,
         await this.repository.operation(tx, userId, id),
@@ -330,9 +248,7 @@ export class BankOperationsService {
       }
       if (
         row.kind === BankOperationKind.Expense &&
-        (await tx.bankCardOperation.findFirst({
-          where: { userId, originalExpenseId: id, deletedAt: null },
-        }))
+        (await this.repository.dependentRefund(tx, userId, id))
       ) {
         conflict(BankErrorCode.DependentRefunds);
       }
@@ -342,27 +258,15 @@ export class BankOperationsService {
           userId,
           row.originalExpenseId,
         );
-        if (
-          (
-            await tx.bankCardOperation.updateMany({
-              where: { id: source.id, userId, version: source.version },
-              data: { version: { increment: 1 } },
-            })
-          ).count !== EXPECTED_UPDATED_ROWS
-        ) {
-          conflict();
-        }
-      }
-      if (
-        (
-          await tx.bankCardOperation.updateMany({
-            where: { id, userId, version, deletedAt: null },
-            data: { deletedAt: new Date(), version: { increment: 1 } },
-          })
-        ).count !== EXPECTED_UPDATED_ROWS
-      ) {
-        conflict();
+        await this.repository.updateOperation(tx,
+          { id: source.id, userId, version: source.version },
+          { version: { increment: 1 } },
+        );
       }
+      await this.repository.updateOperation(tx,
+        { id, userId, version, deletedAt: null },
+        { deletedAt: new Date(), version: { increment: 1 } },
+      );
     });
   }
 
@@ -375,25 +279,13 @@ export class BankOperationsService {
     const period = expenses
       ? undefined
       : periodBounds(query as BankOperationsQueryDto);
-    return this.prisma.$transaction(async (tx) => {
+    return this.repository.read(async (tx) => {
       await this.repository.card(tx, userId, id);
       const limit = query.limit ?? DEFAULT_BANK_PAGE_SIZE,
         page = query.page ?? FIRST_PAGE;
-      const where: Prisma.BankCardOperationWhereInput = {
-        userId,
-        deletedAt: null,
-        OR: [{ cardId: id }, { targetCardId: id }],
-        ...(period
-          ? { date: { gte: period.from, lte: period.to } }
-          : { kind: BankOperationKind.Expense }),
-      };
-      const total = await tx.bankCardOperation.count({ where });
-      const rows = await tx.bankCardOperation.findMany({
-        where,
-        orderBy: [{ date: 'desc' }, { createdAt: 'desc' }, { id: 'desc' }],
-        skip: (page - FIRST_PAGE) * limit,
-        take: limit,
-      });
+      const { total, rows } = await this.repository.operationPage(
+        tx, userId, id, period, limit, page,
+      );
       return {
         items: await this.pageViews(tx, rows),
         total,
diff --git a/src/modules/banking/bank-cards/infrastructure/bank-cards.repository.ts b/src/modules/banking/bank-cards/infrastructure/bank-cards.repository.ts
index 3943cf4..3572f6b 100644
--- a/src/modules/banking/bank-cards/infrastructure/bank-cards.repository.ts
+++ b/src/modules/banking/bank-cards/infrastructure/bank-cards.repository.ts
@@ -1,7 +1,7 @@
 import { Injectable } from '@nestjs/common';
 import { randomUUID } from 'node:crypto';
 
-import { BankCard, Prisma } from '../../../../../generated/prisma/client';
+import { BankCard, BankCardOperation, Prisma } from '../../../../../generated/prisma/client';
 import { isPrismaErrorCode, PrismaErrorCode } from '../../../../prisma/prisma-error-code';
 import { PrismaService } from '../../../../prisma/prisma.service';
 import {
@@ -9,11 +9,13 @@ import {
   conflict,
   missing,
 } from '../application/bank-card-input';
+import { FIRST_PAGE } from '../domain/bank-card-limits';
 import { BankOperationKind } from '../domain/bank-operation-kind';
 
 const INITIAL_RETRY_COUNT = 0;
 const LAST_SEED_OFFSET = 1;
 const EXPECTED_UPDATED_CARDS = 1;
+const EXPECTED_UPDATED_OPERATIONS = 1;
 const EXPECTED_UPDATED_CATEGORIES = 1;
 const VERSION_INCREMENT = 1;
 
@@ -57,6 +59,103 @@ export class BankCardsRepository {
     });
   }
 
+  operationById(tx: Tx, id: string) {
+    return tx.bankCardOperation.findUnique({ where: { id } });
+  }
+
+  createOperation(tx: Tx, data: Prisma.BankCardOperationUncheckedCreateInput) {
+    return tx.bankCardOperation.create({ data });
+  }
+
+  async updateOperation(
+    tx: Tx,
+    where: Prisma.BankCardOperationWhereInput,
+    data: Prisma.BankCardOperationUpdateManyMutationInput,
+  ) {
+    const result = await tx.bankCardOperation.updateMany({ where, data });
+    if (result.count !== EXPECTED_UPDATED_OPERATIONS) conflict();
+  }
+
+  category(tx: Tx, userId: string, id: string) {
+    return tx.expenseCategory.findFirst({ where: { id, userId } });
+  }
+
+  defaultCategory(tx: Tx, userId: string) {
+    return tx.expenseCategory.findUnique({
+      where: { userId_seedKey: { userId, seedKey: 'other' } },
+    });
+  }
+
+  refunds(tx: Tx, userId: string, originalExpenseId: string, excludeId?: string) {
+    return tx.bankCardOperation.findMany({
+      where: {
+        userId,
+        originalExpenseId,
+        deletedAt: null,
+        ...(excludeId ? { id: { not: excludeId } } : {}),
+      },
+    });
+  }
+
+  dependentRefund(tx: Tx, userId: string, originalExpenseId: string) {
+    return tx.bankCardOperation.findFirst({
+      where: { userId, originalExpenseId, deletedAt: null },
+    });
+  }
+
+  async operationViewData(tx: Tx, userId: string, rows: BankCardOperation[]) {
+    const cardIds = new Set(rows.flatMap((row) =>
+      [row.cardId, row.targetCardId].filter((id): id is string => id !== null),
+    ));
+    const sourceIds = new Set(rows.flatMap((row) =>
+      row.originalExpenseId ? [row.originalExpenseId] : [],
+    ));
+    const [cards, sources] = await Promise.all([
+      tx.bankCard.findMany({ where: { userId, id: { in: [...cardIds] } } }),
+      tx.bankCardOperation.findMany({ where: { userId, id: { in: [...sourceIds] } } }),
+    ]);
+    const categoryIds = new Set(rows.map((row) =>
+      sources.find((source) => source.id === row.originalExpenseId)?.categoryId ?? row.categoryId,
+    ).filter((id): id is string => id !== null));
+    const expenseIds = new Set(rows.flatMap((row) => {
+      const source = sources.find((item) => item.id === row.originalExpenseId);
+      return row.kind === BankOperationKind.Expense || source ? [source?.id ?? row.id] : [];
+    }));
+    const [categories, refunds] = await Promise.all([
+      tx.expenseCategory.findMany({ where: { userId, id: { in: [...categoryIds] } } }),
+      tx.bankCardOperation.findMany({
+        where: { userId, originalExpenseId: { in: [...expenseIds] }, deletedAt: null },
+      }),
+    ]);
+    return { cards, sources, categories, refunds };
+  }
+
+  async operationPage(
+    tx: Tx,
+    userId: string,
+    id: string,
+    period: undefined | { from: string; to: string },
+    limit: number,
+    page: number,
+  ) {
+    const where: Prisma.BankCardOperationWhereInput = {
+      userId,
+      deletedAt: null,
+      OR: [{ cardId: id }, { targetCardId: id }],
+      ...(period
+        ? { date: { gte: period.from, lte: period.to } }
+        : { kind: BankOperationKind.Expense }),
+    };
+    const total = await tx.bankCardOperation.count({ where });
+    const rows = await tx.bankCardOperation.findMany({
+      where,
+      orderBy: [{ date: 'desc' }, { createdAt: 'desc' }, { id: 'desc' }],
+      skip: (page - FIRST_PAGE) * limit,
+      take: limit,
+    });
+    return { total, rows };
+  }
+
   cardById(tx: Tx, id: string) {
     return tx.bankCard.findUnique({ where: { id } });
   }