Be able to change decimal precision (Certain currencies don't use decimals)

[freivokh]

Problem

The invoice generator currently applies a fixed decimal precision (typically 2 decimal places) to all currencies, but many currencies don't use decimal places at all. This creates incorrect formatting for currencies like:

• TWD (Taiwan Dollar) - Uses whole numbers only
• JPY (Japanese Yen) - Uses whole numbers only
• KRW (South Korean Won) - Uses whole numbers only
• VND (Vietnamese Dong) - Uses whole numbers only

Current Behavior

When generating an invoice with currency: "TWD" and amount: 1000, the output shows:

NT$1,000.00

Expected Behavior

For TWD and similar currencies, it should show:

NT$1,000

Proposed Solution

Add support for currency-specific decimal precision, either through:

1. Automatic detection based on currency code:

const CURRENCY_DECIMALS = {
  'USD': 2, 'EUR': 2, 'CAD': 2, 'GBP': 2,
  'TWD': 0, 'JPY': 0, 'KRW': 0, 'VND': 0,
  'BHD': 3, 'KWD': 3  // Some currencies use 3 decimals
};

2. Manual override parameter:

{
  currency: "TWD",
  decimal_places: 0,  // New optional parameter
  // ... other invoice data
}

Use Cases

• Business invoicing in Asian markets (Taiwan, Japan, Korea)
• E-commerce platforms handling multiple currencies
• Financial applications requiring accurate currency display

Additional Context

This follows ISO 4217 currency standards where each currency has a defined minor unit. For example:

• USD minor unit = 2 (cents)
• TWD minor unit = 0 (no subdivision)
• JPY minor unit = 0 (no subdivision)

[jaredk2g]

Can you please provide an API call that reproduces this behavior?

[freivokh]

@jaredk2g Sure! if this is what you mean, here is an API call that reproduces the decimal precision issue:

curl -X POST https://invoice-generator.com \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Company ABC\nTaipei, Taiwan",
    "to": "Client XYZ\nTaipei, Taiwan",
    "currency": "TWD",
    "number": "INV-001",
    "date": "2024-01-15",
    "items": [
        {
            "name": "Consulting Service",
            "description": "Technical consulting services",
            "quantity": 1,
            "unit_cost": 31020
        }
    ],
    "fields": {
        "tax": "%",
        "discounts": false,
        "shipping": false
    },
    "tax": 2.1
}'

Current result:

• Rate: NT$31,020.00
• Amount: NT$31,020.00
• Tax (2.1%): NT$651.42
• Total: NT$31,671.42

Expected result for TWD:

• Rate: NT$31,020
• Amount: NT$31,020
• Tax (2.1%): NT$651
• Total: NT$31,671

It would be amazing to specify the decimal precision or have it adjust automatically for currencies with zero decimals 🙏

As invoices in these zero decimal countries, as you would expect, never show decimals

[jaredk2g]

Thank you for the detailed report. We are following the ISO 4217 standard that calls for the minor unit of the TWD currency to be 2 decimal places. While we would not change the default to deviate from ISO 4217, I agree with you in making this customizable with an additional parameter. This additional parameter is an improvement we will consider for a future update.

[freivokh]

Thank you @jaredk2g . Ah I missed that about Taiwan ISO 4217 standard, however I can confirm 99.9% of the invoices and even bank statements in Taiwan omit the 2 decimal places. So adding a customizable parameter would be extremely helpful!

When can we expect this update?