diff --git a/app/models/system_settings.py b/app/models/system_settings.py
new file mode 100644
index 0000000..7f026b3
--- /dev/null
+++ b/app/models/system_settings.py
@@ -0,0 +1,48 @@
+"""System settings model — singleton company master data per tenant."""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, Index, Integer, String
+from sqlalchemy.dialects.postgresql import UUID as PGUUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.core.db import Base, TenantMixin
+
+
+class SystemSettings(Base, TenantMixin):
+    """Singleton system settings per tenant — company master data for invoices/quotes."""
+
+    __tablename__ = "system_settings"
+    __table_args__ = (
+        Index("ix_system_settings_tenant", "tenant_id"),
+    )
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    company_name: Mapped[str] = mapped_column(String(200), nullable=False)
+    company_legal_form: Mapped[str | None] = mapped_column(String(50), nullable=True)
+    company_street: Mapped[str] = mapped_column(String(255), nullable=False)
+    company_city: Mapped[str] = mapped_column(String(100), nullable=False)
+    company_zip: Mapped[str] = mapped_column(String(20), nullable=False)
+    company_country: Mapped[str] = mapped_column(String(2), nullable=False)
+    tax_number: Mapped[str | None] = mapped_column(String(50), nullable=True)
+    vat_id: Mapped[str | None] = mapped_column(String(50), nullable=True)
+    iban: Mapped[str | None] = mapped_column(String(34), nullable=True)
+    bic: Mapped[str | None] = mapped_column(String(11), nullable=True)
+    bank_name: Mapped[str | None] = mapped_column(String(100), nullable=True)
+    ceo: Mapped[str | None] = mapped_column(String(100), nullable=True)
+    trade_register: Mapped[str | None] = mapped_column(String(100), nullable=True)
+    default_currency_id: Mapped[uuid.UUID | None] = mapped_column(
+        PGUUID(as_uuid=True), ForeignKey("currencies.id", ondelete="SET NULL"), nullable=True
+    )
+    default_tax_id: Mapped[uuid.UUID | None] = mapped_column(
+        PGUUID(as_uuid=True), ForeignKey("tax_rates.id", ondelete="SET NULL"), nullable=True
+    )
+    invoice_prefix: Mapped[str] = mapped_column(String(20), nullable=False, default="RE-")
+    quote_prefix: Mapped[str] = mapped_column(String(20), nullable=False, default="AN-")
+    payment_terms_days: Mapped[int] = mapped_column(Integer, nullable=False, default=14)
+    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)