Shipping to UK for the first time

I am stuck deciding between DDP and DDU.
I spent hundreds of dollars paying a UK company to help me get VAT certified, and after months of waiting, finally received my VAT number. (My company is not based in UK).

My (China based) shipping agent is telling me that I dont need a VAT number after all – I can just use DDP instead of DDU. She wants to deflate the value of the goods to save me on taxes, but I worry about this when it comes to my VAT accounting, as my VAT agent wants me to tell them the price of my goods, and I dont want a (15-20 GBP) discrepancy between the value on my incoming shipment and my eventual VAT reporting.

It seems too good to be true that I dont need a VAT number after all… I want to do things by the book.
I’ve searched online but havent been able to find anything that gives me a satisfactory answer.

What the heck should I do?