Invoice

Overview

The Invoice component generates a professional invoice PDF from structured data. No manual layout code needed — just provide the data and gpdf handles the formatting.

Usage

import "github.com/gpdf-dev/gpdf/template"

doc := template.Invoice(template.InvoiceData{
    Number:  "#INV-2026-001",
    Date:    "March 1, 2026",
    DueDate: "March 31, 2026",
    From: template.InvoiceParty{
        Name:    "ACME Corporation",
        Address: []string{"123 Business Street", "Suite 100", "San Francisco, CA 94105"},
    },
    To: template.InvoiceParty{
        Name:    "John Smith",
        Address: []string{"Tech Solutions Inc.", "456 Client Avenue", "New York, NY 10001"},
    },
    Items: []template.InvoiceItem{
        {Description: "Web Development - Frontend", Quantity: "40 hrs", UnitPrice: 150.00, Amount: 6000.00},
        {Description: "Web Development - Backend", Quantity: "60 hrs", UnitPrice: 150.00, Amount: 9000.00},
        {Description: "UI/UX Design", Quantity: "20 hrs", UnitPrice: 120.00, Amount: 2400.00},
        {Description: "Database Design", Quantity: "15 hrs", UnitPrice: 130.00, Amount: 1950.00},
        {Description: "QA Testing", Quantity: "25 hrs", UnitPrice: 100.00, Amount: 2500.00},
        {Description: "Project Management", Quantity: "10 hrs", UnitPrice: 140.00, Amount: 1400.00},
    },
    TaxRate:  10,
    Currency: "$",
    Payment: &template.InvoicePayment{
        BankName: "First National Bank",
        Account:  "1234-5678-9012",
        Routing:  "021000021",
    },
    Notes: "Thank you for your business!",
})

data, err := doc.Generate()

┌─ A4 ──────────────────────────────────────────────┐
│                                                   │
│  ACME Corporation               INVOICE           │
│  123 Business Street       #INV-2026-001          │
│  Suite 100                 Date: March 1, 2026    │
│  San Francisco, CA 94105   Due: March 31, 2026    │
│  ──────────────────────────────────────────────── │
│                                                   │
│  Bill To:                  Payment Info:          │
│  John Smith                First National Bank     │
│  Tech Solutions Inc.       Acct: 1234-5678-9012   │
│  456 Client Avenue         Routing: 021000021     │
│  New York, NY 10001                               │
│                                                   │
│  ┌──────────────┬────────┬──────────┬──────────┐  │
│  │ Description  │  Qty   │Unit Price│  Amount  │  │
│  ├──────────────┼────────┼──────────┼──────────┤  │
│  │ Frontend     │ 40 hrs │  $150.00 │$6,000.00 │  │
│  │ Backend      │ 60 hrs │  $150.00 │$9,000.00 │  │
│  │ UI/UX Design │ 20 hrs │  $120.00 │$2,400.00 │  │
│  │ Database     │ 15 hrs │  $130.00 │$1,950.00 │  │
│  │ QA Testing   │ 25 hrs │  $100.00 │$2,500.00 │  │
│  │ PM           │ 10 hrs │  $140.00 │$1,400.00 │  │
│  └──────────────┴────────┴──────────┴──────────┘  │
│                                                   │
│                        Subtotal: $23,250.00       │
│                        Tax (10%):  $2,325.00      │
│                        ──────────────────         │
│                        Total:    $25,575.00       │
│                                                   │
│  ──────────────────────────────────────────────── │
│          Thank you for your business!             │
│                                                   │
└───────────────────────────────────────────────────┘

Data Types

InvoiceData

Field	Type	Description
`Number`	`string`	Invoice number
`Date`	`string`	Invoice date
`DueDate`	`string`	Payment due date
`From`	`InvoiceParty`	Sender information
`To`	`InvoiceParty`	Recipient information
`Items`	`[]InvoiceItem`	Line items
`TaxRate`	`float64`	Tax rate percentage (e.g., 10 for 10%)
`Currency`	`string`	Currency symbol (e.g., "$", "EUR")
`Notes`	`string`	Footer note
`Payment`	`*InvoicePayment`	Optional payment information

InvoiceParty

type InvoiceParty struct {
    Name    string
    Address []string
}

InvoiceItem

type InvoiceItem struct {
    Description string
    Quantity    string
    UnitPrice   float64
    Amount      float64
}

InvoicePayment

type InvoicePayment struct {
    BankName string
    Account  string
    Routing  string
}

Customization

Pass document options to customize the invoice:

fontData, _ := os.ReadFile("fonts/NotoSansJP-Regular.ttf")

doc := template.Invoice(invoiceData,
    template.WithFont("NotoSansJP", fontData),
    template.WithDefaultFont("NotoSansJP", 12),
    template.WithPageSize(document.Letter),
)

Using the Facade

The gpdf facade re-exports the Invoice constructor:

import "github.com/gpdf-dev/gpdf"

doc := gpdf.NewInvoice(invoiceData)