InvoiceTemplate

The InvoiceTemplate interface represents a reusable invoice template that can be used to quickly generate new invoices with predefined items, customer details, and settings.

string

required

Unique identifier for the template

name

string

required

Display name for the template (e.g., “Monthly Retainer”, “Consulting Services”)

description

string

Optional description explaining when or how to use this template

customer

Partial<Customer>

required

Show Partial customer object

Partial customer information. All customer fields are optional, allowing templates to specify only common fields like country or state. See Customer for available fields.

items

Partial<InvoiceItem>[]

required

Show Array of partial invoice items

Predefined line items with optional fields. Typically includes description and rate, while quantity can be filled in when creating an invoice. See InvoiceItem for available fields.

notes

string

Optional default notes or terms to include on invoices created from this template

taxRate

number

Optional default tax rate as a percentage (e.g., 10 for 10%)

currency

string

required

Three-letter ISO 4217 currency code (e.g., “USD”, “EUR”, “GBP”)

createdAt

string

required

Timestamp when the template was created in ISO 8601 format

TypeScript definition

export interface InvoiceTemplate {
  id: string;
  name: string;
  description?: string;
  customer: Partial<Customer>;
  items: Partial<InvoiceItem>[];
  notes?: string;
  taxRate?: number;
  currency: string;
  createdAt: string;
}

Example

const template: InvoiceTemplate = {
  id: "tmpl_abc123",
  name: "Web Development - Monthly Retainer",
  description: "Standard monthly retainer for ongoing web development services",
  customer: {
    // Leave most fields empty for flexibility
    country: "United States",
    state: "CA"
  },
  items: [
    {
      description: "Monthly Development Hours",
      rate: 150,
      // quantity will be filled in per invoice
    },
    {
      description: "Project Management",
      quantity: 1,
      rate: 500
    },
    {
      description: "Hosting & Maintenance",
      quantity: 1,
      rate: 200
    }
  ],
  notes: "Payment due within 30 days. Includes up to 2 hours of support.",
  taxRate: 8.5,
  currency: "USD",
  createdAt: "2026-01-15T12:00:00Z"
};

Creating invoices from templates

Templates serve as blueprints for new invoices. When creating an invoice from a template:

Copy predefined items and fill in missing quantities
Merge template customer data with specific customer details
Use template defaults for currency, tax rate, and notes
Generate new invoice-specific fields (id, invoiceNumber, dates, status)

import type { Invoice, InvoiceTemplate } from './types';

function createInvoiceFromTemplate(
  template: InvoiceTemplate,
  customer: Customer,
  overrides?: Partial<Invoice>
): Invoice {
  return {
    id: generateId(),
    invoiceNumber: generateInvoiceNumber(),
    date: new Date().toISOString(),
    dueDate: addDays(new Date(), 30).toISOString(),
    status: "draft",
    customer: {
      ...template.customer,
      ...customer // Override template customer with actual customer
    },
    items: template.items.map(item => ({
      id: generateId(),
      description: item.description || "",
      quantity: item.quantity || 1,
      rate: item.rate || 0,
      discount: item.discount,
      taxRate: item.taxRate
    })),
    notes: template.notes,
    taxRate: template.taxRate,
    currency: template.currency,
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
    ...overrides
  };
}

Use cases

Templates are useful for:

Recurring services: Monthly retainers with standard line items
Package deals: Predefined service bundles at set prices
Industry-specific invoices: Templates for common services in your industry
Multi-currency invoicing: Separate templates for different currencies
Regional variations: Templates with different tax rates or terms by region

Overview

Endpoints

Types

InvoiceTemplate