Dispute with UPS over incorrect invoices

In 2023 I was subject to a routine compliance investigation by HMRC. It was found that even though I provided exact correct commercial invoices to UPS 50% of the time they were creating invoices based on incorrect values. I was only about £5 out at the end of the investigation. I was told by HMRC that I needed to ensure the invoices were correct and if incorrect then to put them under query. When correct they meant correct values, quantities, tariff codes etc. Since then I have checked every UPS invoice and found 50% to be incorrect. They were all put under query with UPS post clearance. I have about 15 invoices totalling £20k+ under query. UPS are now threatening legal action (ironically at a time I cannot work due to a bad accident). I have finally found someone good at UPS who is helping me rectify their mistakes, however, there are some invoices which have to correct amount but crucially have used incorrect tariff codes. The lady I spoke to at HMRC said I need to get these amended. The C18 team said UPS should contact them to amend yet UPS say its a non-monetary amendment so they are unwilling to amend. I am stuck between a rock and a hard place. UPS wanting to take me to court and me wanting to get the record right as per the HMRC advice. I am looking for some statutes or guidance I can give UPS to back up my argument as I do not wish to be taken to court by them, nor incur penalties for use of incorrect tariff codes

Hi I am not from HMRC but usually it would be the customs declaration made by UPS that HMRC requires to be correct and subject to amendment if incorrect. The invoice from UPS for their services would be a commercial matter and not something HMRC would need to be amended. If UPS are also paying customs duty on your behalf they would also invoice for that, but again this is a commercial arrangement. Do you mean you are withholding payment to UPS until they rectify the customs declaration? And this is why UPS are threatening legal action?If so this is also a commercial matter. You do need to identify why UPS are not using the invoice values or commodity codes being provided to them. Do bear in mind how the value for customs is determined. E.g there will possibly be additions for the cost of getting goods to the UK , and if invoiced in another currency the value will be converted to GBP using a customs exchange rate. If incorrect commodity codes have been used but there is no impact on duty payable then HMRC post clearance team do need to be notified. Whilst ideally UPS should do this if they haven’t used the commodity codes you have given them you can also do this yourself. Similarly with any over or underpayments. Perhaps one of the HMRC Admins can provide links.

Hi Dottie2025
If a non monetary amendment of the import declaration is required you can contact our imports/exports helpline for contact details of Post Clearance Amendments (PCA) team. 
You can find their contact details on below link.
Imports and exports: general enquiries
Thank you