Credinote allocation against invoice

Need to know how to allocate credit note against invoice using API, please let me know which APi should I use for it.

Hi there,

FreeAgent doesn’t allocate credit notes against specific invoices, but against a contact’s account. To create a credit note, you need to create an invoice with negative values, e.g.

POST https://api.freeagent.com/v2/invoices

{
  "invoice": {  
    "contact": "https://api.freeagent.com/v2/contacts/24",
    "dated_on": "2017-02-07",
    "payment_terms_in_days": 30,
    "invoice_items": [
      {
        "description": "Vital Work",
        "item_type": "Hours",
        "price": "-10.0",
        "quantity": "1.0",
        "sales_tax_rate": "20.0",
        "category": "https://api.freeagent.com/v2/categories/001"
      }
    ]
  }
}

Full documentation for invoices (and credit notes) is available at https://dev.freeagent.com/docs/invoices

Hope that helps,
Paul.