Krishna Trivedi

Hi All, My client is registered in UK and they have one customer from the Republic of Ireland. This customer trades only on DDP terms. Hence my client were obliged to open an IE Vat number. This means that my client sell to the customer with Irish VAT reference, charging local 23% Vat and submit VAT returns in IE. My client doesn't have any establishment in Ireland. Customer has issues and sent debit note for administrative charges to my client. How my client can record it in their as per HMRC provisions ? Does these debit note will fall into IRIS framework or under reverse charge as per UK rules? Please advice.