invoice-document-pdf

Invoice & Document PDF Generation

Generate professional business documents — invoices, contracts, receipts, forms — as polished PDFs. This skill covers templates, data-driven generation, batch processing, digital signatures, and workflow automation.

Invoice PDF Structure

A professional invoice follows a standard layout that makes it easy to process, pay, and reconcile.

Standard Invoice Anatomy

┌───────────────────────────────────────────┐
│  [LOGO]           INVOICE                  │
│  Your Company     #INV-2025-0042          │
│  123 Business Rd                           │
│  City, State ZIP                           │
├─────────────────┬─────────────────────────┤
│  Bill To:       │  Invoice Details:        │
│  Client Name    │  Date: 2025-01-15       │
│  Client Address │  Due: 2025-02-14        │
│  City, State    │  Terms: Net 30          │
│                 │  PO #: PO-2025-001      │
├─────────────────┴─────────────────────────┤
│  # │ Description        │ Qty │ Rate│ Amt │
│  ───┼───────────────────┼─────┼─────┼─────┤
│  1 │ Web Development   │  40 │ 150 │$6,000│
│  2 │ UI/UX Design      │  20 │ 125 │$2,500│
│  3 │ DevOps Setup      │   8 │ 175 │$1,400│
├────────────────────────┴─────┴─────┴─────┤
│  Subtotal:                          $9,900 │
│  Tax (8%):                            $792 │
│  Discount (5%):                      -$495 │
│  Total:                            $10,197 │
├───────────────────────────────────────────┤
│  Payment Information:                      │
│  Bank: First National Bank                 │
│  Account: XXXX-XXXX-1234                   │
│  Routing: 021000021                        │
│  PayPal: [email protected]                   │
├───────────────────────────────────────────┤
│  Terms & Notes:                            │
│  Payment due within 30 days.               │
│  Late payment subject to 1.5%/mo fee.      │
└───────────────────────────────────────────┘

Invoice Data Model

"""Invoice data model with validation."""

from dataclasses import dataclass, field
from datetime import datetime, timedelta
from decimal import Decimal
from typing import Optional, list
import uuid


@dataclass
class LineItem:
    """A single line item on an invoice."""
    description: str
    quantity: Decimal
    unit_price: Decimal
    sku: Optional[str] = None
    
    @property
    def amount(self) -> Decimal:
        return self.quantity * self.unit_price


@dataclass
class InvoiceData:
    """Complete invoice data structure."""
    # Invoice identifiers
    invoice_number: str
    po_number: Optional[str] = None
    
    # Dates
    issue_date: str = field(default_factory=lambda: datetime.now().strftime("%Y-%m-%d"))
    due_date: Optional[str] = None
    payment_terms: str = "Net 30"
    
    # Seller (Your company)
    seller_name: str = ""
    seller_address: str = ""
    seller_city: str = ""
    seller_state: str = ""
    seller_zip: str = ""
    seller_phone: str = ""
    seller_email: str = ""
    seller_logo_path: Optional[str] = None
    tax_id: Optional[str] = None
    
    # Buyer (Client)
    client_name: str = ""
    client_address: str = ""
    client_city: str = ""
    client_state: str = ""
    client_zip: str = ""
    client_email: Optional[str] = None
    
    # Line items
    line_items: list[LineItem] = field(default_factory=list)
    
    # Financial
    tax_rate: Decimal = Decimal("0")
    discount_rate: Decimal = Decimal("0")
    discount_description: str = "Discount"
    currency_symbol: str = "$"
    
    # Payment
    bank_name: Optional[str] = None
    bank_account: Optional[str] = None
    bank_routing: Optional[str] = None
    payment_instructions: Optional[str] = None
    
    # Notes
    notes: Optional[str] = None
    terms: Optional[str] = None
    
    def __post_init__(self):
        if not self.due_date:
            due = datetime.now() + timedelta(days=30)
            self.due_date = due.strftime("%Y-%m-%d")
        if not self.invoice_number:
            self.invoice_number = f"INV-{datetime.now().strftime('%Y%m')}-{uuid.uuid4().hex[:6].upper()}"
    
    @property
    def subtotal(self) -> Decimal:
        return sum(item.amount for item in self.line_items)
    
    @property
    def tax_amount(self) -> Decimal:
        return self.subtotal * self.tax_rate
    
    @property
    def discount_amount(self) -> Decimal:
        return self.subtotal * self.discount_rate
    
    @property
    def total(self) -> Decimal:
        return self.subtotal + self.tax_amount - self.discount_amount