diff --git a/DOCS.md b/DOCS.md
index 3c57447..6c1e3e6 100644
--- a/DOCS.md
+++ b/DOCS.md
@@ -126,7 +126,7 @@ An account is a place money lives — a bank account, a card, a cash wallet. Eve
 to exactly one account (transfers touch two). Balances are **derived** from transactions, not
 stored — there's no "set balance" endpoint.
 
-**`AccountType`:** `checking` · `savings` · `credit_card` · `cash` · `investment` · `other`
+**`AccountType`:** `checking` · `debit_card` · `savings` · `credit_card` · `cash` · `investment` · `other`
 
 | Method | Path | Description |
 |---|---|---|
diff --git a/backend/app/models/enums.py b/backend/app/models/enums.py
index 772c49e..94b06a4 100644
--- a/backend/app/models/enums.py
+++ b/backend/app/models/enums.py
@@ -4,6 +4,7 @@ import enum
 
 class AccountType(str, enum.Enum):
     CHECKING = "checking"
+    DEBIT_CARD = "debit_card"
     SAVINGS = "savings"
     CREDIT_CARD = "credit_card"
     CASH = "cash"
diff --git a/backend/app/services/insights_service.py b/backend/app/services/insights_service.py
index 8473e19..4da40fc 100644
--- a/backend/app/services/insights_service.py
+++ b/backend/app/services/insights_service.py
@@ -33,7 +33,7 @@ MAX_LOOKBACK_MONTHS = 24
 # Accounts where a big, untouched balance means money isn't working — a
 # credit card balance isn't "your cash", an investment account is already
 # invested, and OTHER is too ambiguous to guess at.
-_IDLE_CASH_ACCOUNT_TYPES = (AccountType.CHECKING, AccountType.SAVINGS, AccountType.CASH)
+_IDLE_CASH_ACCOUNT_TYPES = (AccountType.CHECKING, AccountType.DEBIT_CARD, AccountType.SAVINGS, AccountType.CASH)
 
 
 def _previous_month(year: int, month: int) -> tuple[int, int]:
diff --git a/backend/app/services/net_worth_service.py b/backend/app/services/net_worth_service.py
index 617cc22..5128f48 100644
--- a/backend/app/services/net_worth_service.py
+++ b/backend/app/services/net_worth_service.py
@@ -2,7 +2,7 @@
 asset class.
 
 Design note: "Cash" is not stored anywhere — it's derived live from
-Account/Transaction data (checking/savings/cash/investment accounts) so the
+Account/Transaction data (checking/debit-card/savings/cash/investment accounts) so the
 Transactions feature stays the single source of truth for liquid money.
 Investment accounts count here too: their balance is uninvested/unallocated
 money sitting on the account, not the market value of what's actually
@@ -36,7 +36,13 @@ from app.schemas.net_worth import (
     RiskLevelSummary,
 )
 
-CASH_ACCOUNT_TYPES = {AccountType.CHECKING, AccountType.SAVINGS, AccountType.CASH, AccountType.INVESTMENT}
+CASH_ACCOUNT_TYPES = {
+    AccountType.CHECKING,
+    AccountType.DEBIT_CARD,
+    AccountType.SAVINGS,
+    AccountType.CASH,
+    AccountType.INVESTMENT,
+}
 
 RANGE_DAYS = {"30d": 30, "90d": 90, "1y": 365, "5y": 365 * 5}
 
diff --git a/backend/tests/test_accounts.py b/backend/tests/test_accounts.py
new file mode 100644
index 0000000..e968d45
--- /dev/null
+++ b/backend/tests/test_accounts.py
@@ -0,0 +1,34 @@
+"""Account-type behavior shared by the accounts API and financial summaries."""
+from datetime import date
+
+from httpx import AsyncClient
+
+from tests.helpers import money, txn_payload
+
+
+async def test_debit_card_is_a_liquid_account_type(client: AsyncClient, categories):
+    response = await client.post(
+        "/accounts",
+        json={"name": "Debit card", "type": "debit_card", "currency": "RUB"},
+    )
+
+    assert response.status_code == 201
+    debit_card = response.json()
+    assert debit_card["type"] == "debit_card"
+
+    transaction = await client.post(
+        "/transactions",
+        json=txn_payload(
+            debit_card["id"],
+            type="income",
+            amount="1000.00",
+            category_id=categories["Salary"]["id"],
+            date=date.today().isoformat(),
+        ),
+    )
+    assert transaction.status_code == 201
+
+    summary = await client.get("/net-worth/summary", params={"range": "all"})
+
+    assert summary.status_code == 200
+    assert money(summary.json()["current"]) == money("1000.00")
diff --git a/backend/tests/test_insights.py b/backend/tests/test_insights.py
index 2423aa4..fe0e14a 100644
--- a/backend/tests/test_insights.py
+++ b/backend/tests/test_insights.py
@@ -51,6 +51,25 @@ async def test_idle_cash_ignores_investment_accounts(client: AsyncClient, catego
     assert "idle_cash" not in await _alert_keys(client)
 
 
+async def test_idle_cash_includes_debit_cards(client: AsyncClient, categories):
+    debit_card = await client.post(
+        "/accounts", json={"name": "Debit card", "type": "debit_card", "currency": "USD"}
+    )
+    debit_card_id = debit_card.json()["id"]
+    await client.post(
+        "/transactions",
+        json=_txn(
+            debit_card_id,
+            type="income",
+            amount="5000.00",
+            category_id=categories["Salary"]["id"],
+            date=STALE_DATE,
+        ),
+    )
+
+    assert "idle_cash" in await _alert_keys(client)
+
+
 async def test_idle_cash_respects_custom_threshold(client: AsyncClient, account_id, categories):
     await client.post(
         "/transactions",
diff --git a/frontend/src/components/accounts/AccountFormModal.tsx b/frontend/src/components/accounts/AccountFormModal.tsx
index bc26604..cffb528 100644
--- a/frontend/src/components/accounts/AccountFormModal.tsx
+++ b/frontend/src/components/accounts/AccountFormModal.tsx
@@ -12,7 +12,7 @@ interface AccountFormModalProps {
   account?: Account | null;
 }
 
-const ACCOUNT_TYPES: AccountType[] = ["checking", "savings", "credit_card", "cash", "investment", "other"];
+const ACCOUNT_TYPES: AccountType[] = ["checking", "debit_card", "savings", "credit_card", "cash", "investment", "other"];
 
 const EMPTY_FORM = { name: "", type: "checking" as AccountType };
 
diff --git a/frontend/src/components/accounts/AccountList.tsx b/frontend/src/components/accounts/AccountList.tsx
index 1253ad1..164f712 100644
--- a/frontend/src/components/accounts/AccountList.tsx
+++ b/frontend/src/components/accounts/AccountList.tsx
@@ -12,6 +12,7 @@ interface AccountListProps {
 
 const TYPE_ICONS: Record<AccountType, LucideIcon> = {
   checking: Wallet,
+  debit_card: CreditCard,
   savings: PiggyBank,
   credit_card: CreditCard,
   cash: Banknote,
diff --git a/frontend/src/lib/i18n.ts b/frontend/src/lib/i18n.ts
index ab5bb98..80559d4 100644
--- a/frontend/src/lib/i18n.ts
+++ b/frontend/src/lib/i18n.ts
@@ -424,6 +424,7 @@ const ru = {
   "account.confirmDelete":
     "Удалить счёт «{{name}}»?\n\nЭто безвозвратно удалит и ВСЕ транзакции по этому счёту. Если хотите сохранить историю, заархивируйте счёт вместо удаления.",
   "account.type.checking": "Текущий счёт",
+  "account.type.debit_card": "Дебетовая карта",
   "account.type.savings": "Накопительный счёт",
   "account.type.credit_card": "Кредитная карта",
   "account.type.cash": "Наличные",
@@ -918,6 +919,7 @@ const en: Record<keyof typeof ru, string> = {
   "account.confirmDelete":
     "Delete the account “{{name}}”?\n\nThis will permanently delete ALL transactions on this account too. If you want to keep the history, archive the account instead of deleting it.",
   "account.type.checking": "Checking",
+  "account.type.debit_card": "Debit card",
   "account.type.savings": "Savings",
   "account.type.credit_card": "Credit card",
   "account.type.cash": "Cash",
diff --git a/frontend/src/types/index.ts b/frontend/src/types/index.ts
index 7334717..7d44162 100644
--- a/frontend/src/types/index.ts
+++ b/frontend/src/types/index.ts
@@ -1,4 +1,4 @@
-export type AccountType = "checking" | "savings" | "credit_card" | "cash" | "investment" | "other";
+export type AccountType = "checking" | "debit_card" | "savings" | "credit_card" | "cash" | "investment" | "other";
 export type CategoryKind = "income" | "expense";
 export type TransactionType = "income" | "expense" | "transfer";
 export type RecurringFrequency = "weekly" | "monthly" | "yearly";