Imported a single carbon rim from China.

Value of item and postage is $180 as marked on the docket. That’s £136.

The duty, VAT and handling fee were £71.83!

That’s not right is it? There are no tariffs that I’m missing are there? It should just be ~25% so £30 plus the £12 handling fee?

Have you looked up the duty code for a wheel? Rates vary per product type. Also what is the handling fee? I’ve seen this range from £8 – £30 depending on the courier service.

Could be this:
Tariffs from China
48.5% duty on some cycle parts from China.

You’re missing vat at 20%, no?

Does the invoice separate the postage fee from the value of the rim?
I had an issue with some Litespeed spares sent from the states, only the total figure was put on the customs form with no postage itemised and the handler assumed a nominal figure for the shipping and put it on top. This added £30 (just double checked) to the release fee. I challenged it with a copy of the full invoice and it was accepted and the bill reduced accordingly

Duty is paid on the value of the item plus carriage plus insurance then VAT is applied to that total, see here – https://www.gov.uk/goods-sent-from-abroad/tax-and-duty. Release fee then depends on the total.

I paid less than £40 including the processing rate for a pair of carbon wheels.

Purchase price was £250 but the parcel had $100 value put on it by the supplier

I paid less than £40 including the processing rate for a pair of carbon wheels.

Correctly declared one has no bearing on the other. Wheel parts are as likely to fall into the same commodity grouping as sheep* as they are wheels. Your wheels should have been declared as of aluminium or other alloys of base metal due to spokes and hubs not as carbon.
Carbon rims obviously not.

*Obviously not but you get the gist.

So – I filled in the paperwork to contest the fees and received a 44% (£27) refund reducing my total fees to a more acceptable £45. It’s always worth asking.

Almost 2 months to get an answer, but they did answer.

Seems in the ballpark to me.

You take the value,

Add import duty

Add admin fee

Apply VAT to the whole total.

Do you have a break down of costs?

Yeah, their recalculated math almost exactly matches my own in the OP.

I was a little concerned that the above mentioned anti-dumping tariff had been applied, but it hadn’t. 20% VAT + 3.7% duty.

So – I filled in the paperwork to contest the fees and received a 44% (£27) refund reducing my total fees to a more acceptable £45. It’s always worth asking.

how did you contest it – on the basis of wrong tariff code (did you do some research & suggest alternative?) or just say “it’s too much!! 😭”?

I just queried the amount using the address on the Parcelforce sticker. I gave evidence of the waybill, the values, etc and they (BorderForce) recalculated based on the evidence. I’ve got no idea how ParcelForce/Borderforce calculated it wrong to begin with as all of this evidence was strapped to the parcel as part of the waybill docket.