Invoice Payments

Overview

Managing invoice payments involves three key aspects:

Payment terms: When payment is expected
Payment tracking: Monitoring what’s been paid
Payment reconciliation: Matching payments to invoices

Payment terms

Payment terms define when an invoice must be paid. They consist of two components: a type and a days value.

Payment term types

NET

Payment due a fixed number of days from the invoice date.

curl https://api.nocotax.app/invoices \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -d '{
    "flow": "sales",
    "currency": "EUR",
    "customer_id": "org_customer_123",
    "payment_terms": {
      "type": "NET",
      "days": 30
    },
    "items": [...]
  }'

Examples:

NET 30: Due 30 days from invoice date
NET 15: Due 15 days from invoice date
NET 60: Due 60 days from invoice date

Due date calculation:

Invoice date: January 15, 2025
Payment terms: NET 30
Due date: February 14, 2025

END_OF_MONTH

Payment due a certain number of days after the end of the invoice month.

curl https://api.nocotax.app/invoices \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -d '{
    "flow": "sales",
    "currency": "EUR",
    "customer_id": "org_customer_123",
    "payment_terms": {
      "type": "END_OF_MONTH",
      "days": 30
    },
    "items": [...]
  }'

Examples:

END_OF_MONTH 30: Due the last day of the month of 30 days after
END_OF_MONTH 0: Due on the last day of the invoice month
END_OF_MONTH 45: Due the last day of the month of 45 days after

Due date calculation:

Invoice date: January 15, 2025
Payment terms: END_OF_MONTH 30
+30 days: Feb 14, 2025
Due date: Feb 28, 2025

Setting payment terms

Payment terms can be set when creating an invoice:

curl https://api.nocotax.app/invoices \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -H "Content-Type: application/json" \
  -d '{
    "flow": "sales",
    "currency": "EUR",
    "customer_id": "org_customer_123",
    "payment_terms": {
      "type": "NET",
      "days": 45
    },
    "items": [
      {
        "description": "Annual Subscription",
        "quantity": 1,
        "unit_extratax_amount": 120000
      }
    ]
  }'

Due date calculation

The due_date is automatically calculated when you finalize the invoice:

# Finalize the invoice
curl https://api.nocotax.app/invoices/inv_123/finalize \
  -X POST \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \

# Response includes calculated due_date
{
  "id": "inv_123",
  "status": "FINALIZED",
  "document_date": "2025-01-15",
  "due_date": "2025-02-28",
  "payment_terms": {
    "type": "NET",
    "days": 30
  }
}

If no payment terms are specified, the due_date is not calculated and payment tracking will be less meaningful.

Payment status

Once finalized, invoices track payment status automatically:

OPEN

Invoice is due but the due date hasn’t passed yet.

{
  "payment_status": "OPEN",
  "due_date": "2025-02-14",
  "total_tax_included_amount": 10000,
  "amount_remaining": 10000
}

DUE

Invoice is past its due date and still unpaid.

{
  "payment_status": "DUE",
  "due_date": "2025-01-10",
  "total_tax_included_amount": 10000,
  "amount_remaining": 10000
}

DUE (PARTIALLY PAID)

Invoice has received partial payment, but is still due

{
  "payment_status": "DUE",
  "total_tax_included_amount": 10000,
  "amount_paid": 6000,
  "amount_remaining": 4000
}

PAID

Invoice is fully paid.

{
  "payment_status": "PAID",
  "total_tax_included_amount": 10000,
  "amount_paid": 10000,
  "amount_remaining": 0
}

Attaching payments

Record payments received or made on an invoice.

Full payment

Mark an invoice as fully paid:

curl https://api.nocotax.app/invoices/inv_123/attach_payment \
  -X POST \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -H "Content-Type: application/json" \
  -d '{}'

This marks the invoice as paid with:

Amount: Full amount_remaining
Payment date: Current date
No external reference

Partial payment or detailed record

Record a partial payment with specific amount:

curl https://api.nocotax.app/invoices/inv_123/attach_payment \
  -X POST \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -H "Content-Type: application/json" \
  -d '{
    "transaction_data": {
      "amount": 5000,
      "currency": "EUR",
      "transaction_type": "payment",
      "reference": "PAYxPSP-ch_abc123" // Link to external payment system
    }
  }'

Payment parameters

All these parameters must be nested into a transaction_data field.

Parameter	Type	Description
`amount`	integer	Payment amount in smallest currency unit (optional, defaults to amount_remaining)
`currency`	string	Payment currency
`reference`	string	External payment reference (e.g., Stripe charge ID, bank transfer reference)
`transaction_type`	string	Payment, Transfer

Payment reconciliation

Reconciliation is the process of matching payments to invoices and ensuring balances are accurate.

Automatic reconciliation

When you attach a payment, Nocotax automatically:

Updates amount_remaining: Deducts payment amount
Updates payment_status: Changes to PAID or PARTIALLY_PAID
Adjusts AP/AR balances: Updates organization balances
Records payment history: Tracks all payments on the invoice

Multiple payments

An invoice can have multiple payments:

# First partial payment
curl https://api.nocotax.app/invoices/inv_123/attach_payment \
  -X POST \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -d '{
    "transaction_data": {
      "amount": 3000,
      "currency": "EUR",
      "transaction_type": "payment",
      "reference": "PAYMENT_1"
    }
  }'

# Second partial payment
curl https://api.nocotax.app/invoices/inv_123/attach_payment \
  -X POST \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -d '{
    "transaction_data": {
      "amount": 7000,
      "currency": "EUR",
      "transaction_type": "payment",
      "reference": "PAYMENT_2"
    }
  }'

Credit notes and payment balance

Credit notes affect the payment balance:

# Original invoice: €100
# Customer pays: €100
# Status: PAID

# Issue credit note: -€20
curl https://api.nocotax.app/credit_notes \
  -u ${ACCOUNT_ID}:${YOUR_API_KEY} \
  -d '{
    "flow": "sales",
    "currency": "EUR",
    "customer_id": "org_customer_123",
    "invoice_id": "inv_123",
    "items": [
      {
        "description": "Correction",
        "quantity": 1,
        "unit_extratax_amount": -2000
      }
    ]
  }'

# After finalizing credit note:
# amount_remaining: -€20 (credit balance)
# Status: PAID (but with credit to refund or apply)

The credit note creates a credit balance that can be:

Refunded to the customer
Applied to future invoices
Tracked as credit owed

See Credit Notes for details.

Best practices

Always set payment terms when creating invoices for accurate due date tracking
Use NET terms for fixed payment periods
Use END_OF_MONTH terms for B2B customers who process payments monthly
Include payment references to link to external payment systems
Record partial payments as they’re received
Monitor payment_status to identify overdue invoices

Getting started

Billing and invoicing

Implementation Guides

Overview

Payment terms

Payment term types

NET

END_OF_MONTH

Setting payment terms

Due date calculation

Payment status

OPEN

DUE

DUE (PARTIALLY PAID)

PAID

Attaching payments

Full payment

Partial payment or detailed record

Payment parameters

Payment reconciliation

Automatic reconciliation

Multiple payments

Credit notes and payment balance

Best practices

​Overview

​Payment terms

​Payment term types

​NET

​END_OF_MONTH

​Setting payment terms

​Due date calculation

​Payment status

​OPEN

​DUE

​DUE (PARTIALLY PAID)

​PAID

​Attaching payments

​Full payment

​Partial payment or detailed record

​Payment parameters

​Payment reconciliation

​Automatic reconciliation

​Multiple payments

​Credit notes and payment balance

​Best practices

Overview

Payment terms

Payment term types

NET

END_OF_MONTH

Setting payment terms

Due date calculation

Payment status

OPEN

DUE

DUE (PARTIALLY PAID)

PAID

Attaching payments

Full payment

Partial payment or detailed record

Payment parameters

Payment reconciliation

Automatic reconciliation

Multiple payments

Credit notes and payment balance

Best practices