diff --git a/superfaktura/invoice.py b/superfaktura/invoice.py
new file mode 100644
index 0000000..2110c69
--- /dev/null
+++ b/superfaktura/invoice.py
@@ -0,0 +1,139 @@
+from dataclasses import dataclass, asdict
+from pprint import pprint
+from typing import Optional, List
+import json
+
+from superfaktura.bank_account import BankAccount
+from superfaktura.client_contacts import ClientContactModel
+from superfaktura.enumerations.currency import Currencies
+from superfaktura.superfaktura_api import SuperFakturaAPI
+from utils.data_types import Date, DateEncoder
+
+
+@dataclass
+class InvoiceModel:
+    add_rounding_item: Optional[int] = 0
+    already_paid: Optional[int] = None
+    bank_accounts: Optional[List[dict]] = None
+    comment: Optional[str] = None
+    constant: Optional[str] = None
+    created: Optional[Date] = None
+    delivery: Optional[Date] = None
+    delivery_type: Optional[str] = None
+    deposit: Optional[float] = None
+    discount: Optional[float] = 0
+    discount_total: Optional[float] = None
+    due: Optional[Date] = None
+    estimate_id: Optional[int] = None
+    header_comment: Optional[str] = None
+    internal_comment: Optional[str] = None
+    invoice_currency: Optional[str] = None
+    invoice_no_formatted: Optional[str] = None
+    issued_by: Optional[str] = None
+    issued_by_email: Optional[str] = None
+    issued_by_phone: Optional[str] = None
+    issued_by_web: Optional[str] = None
+    logo_id: Optional[int] = None
+    mark_sent: Optional[int] = None
+    mark_sent_message: Optional[str] = None
+    mark_sent_subject: Optional[str] = None
+    name: Optional[str] = None
+    order_no: Optional[str] = None
+    parent_id: Optional[int] = None
+    paydate: Optional[Date] = None
+    payment_type: Optional[str] = None
+    proforma_id: Optional[str] = None
+    rounding: Optional[str] = None
+    sequence_id: Optional[int] = None
+    specific: Optional[str] = None
+    tax_document: Optional[int] = None
+    type: Optional[str] = None
+    variable: Optional[str] = None
+    vat_transfer: Optional[int] = None
+
+    def as_dict(self) -> dict:
+        data = asdict(self)
+        for key in list(data.keys()):
+            if data[key] is None:
+                del data[key]
+        return data
+
+    def to_dict(self) -> dict:
+        """
+        Converts the Record object to a dictionary for JSON serialization.
+        """
+        return {"due": self.due.to_dict() if self.due else None}
+
+
+@dataclass
+class InvoiceItem:
+    name: str
+    unit_price: float
+    description: Optional[str] = None
+    discount: Optional[float] = 0
+    discount_description: Optional[str] = None
+    load_data_from_stock: int = 0
+    quantity: Optional[float] = 1
+    sku: Optional[str] = None
+    stock_item_id: Optional[int] = None
+    tax: Optional[float] = None
+    unit: Optional[str] = None
+    use_document_currency: Optional[int] = 0
+
+    def as_dict(self) -> dict:
+        data = asdict(self)
+        for key in list(data.keys()):
+            if data[key] is None:
+                del data[key]
+        return data
+
+
+class Invoice(SuperFakturaAPI):
+    def __init__(self):
+        super().__init__()
+
+    def add(
+        self,
+        invoice: InvoiceModel,
+        items: List[InvoiceItem],
+        contact: ClientContactModel,
+    ):
+        data = {
+            "Invoice": invoice.as_dict(),
+            "InvoiceItem": [item.as_dict() for item in items],
+            "Client": contact.as_dict(),
+        }
+        url = "invoices/create"
+        resp = self.post(endpoint=url, data=json.dumps(data, cls=DateEncoder))
+        return resp
+
+
+if __name__ == "__main__":
+    invoice = Invoice()
+    bank = BankAccount()
+    invoice.add(
+        invoice=InvoiceModel(
+            type="proforma",
+            name="Invoice 3",
+            due=Date("2025-02-01"),
+            invoice_currency=Currencies.CZK,
+            header_comment="We invoice you for services",
+            bank_accounts=[bank.default().as_dict()],
+        ),
+        items=[
+            InvoiceItem(name="Services", unit_price=100, quantity=1, unit="ks", tax=21),
+            InvoiceItem(name="SIM card", unit_price=50, quantity=1, tax=21, unit="ks"),
+            InvoiceItem(
+                name="SIM card 2", unit_price=75, quantity=1, tax=21, unit="ks"
+            ),
+        ],
+        contact=ClientContactModel(
+            name="Richard Kubíček",
+            email="kubicekr@eledio.com",
+            phone="+420 123 456 789",
+            address="Jaroslava Foglara 861/1",
+            ico="123",
+            update=True,
+            country_id=57,
+        ),
+    )