Vat question - Self billing invoice

[dig dug dan]

I have recently traded in an old farm trailer and brought a new one through my dealer. They have given me an invoice for the new trailer, with the vat shown, and have given me a seperate "self billing invoice" for the trade in, with no vat.
I am unsure how to claim the vat in this instance?
do i work out how much vat should be on the trade in and minus this from the vat claimed on the new one?

[lemoncurd1702]

Best have a word with your dealer and make sure they know you are vat registered. They must experience this all the time.

If you need to add vat to your sale, which is what your trade in is , should make no difference to your dealer.

[GB_Groundworks]

VAT and part-exchange
If you supply goods or services and receive other goods or services in exchange (or part-exchange) you must account for VAT on the amount the customer would have paid you if they had given you money instead.
Example
The sale price (including VAT) of a camera is £120. If you sell it for cash, the price (excluding VAT) is £100 and you must account for £20 VAT.
If, instead of selling it for cash, you exchange it for £70 plus the customer's old camera, you must still account for VAT based on the sale price of £120 and the VAT due to HM Revenue & Customs (HMRC) would be £20.

More for them than you I guess

[dig dug dan]

This is what i thought
They asked for my VAT number when i did the deal on the trailer, and i phoned the rep today to explain the invoices i had.
Turns out, they should have put down the VAT part of the trailer i am trading in, and they hadn't! so it is the admin office who have made a mistake.
Now it all becomes clear. Why i couldn't have just sent them a vat invoice for my trade in i don't know!