How to import my old laptop?

I'm moving from Dublin to London in a few days, but have a laptop at my brother's in New York that I'd like sent over.

I'm trying to avoid paying any customs or taxes on it, and my understanding is that this is fine because it's a personal possession that I am taking as part of a move.

Is there any specific way I should have him ship this or label it to make sure I don't get taxed? Will including the receipt from the laptop proving that it is over 6 months old be enough or should I have him fill out that C3 customs form?

Any advice would be appreciated.

I had a computer shipped to me by UPS and it was pretty simple. The outgoing customs form just said that it was a computer for personal use that had been used in the US since whatever date.

When it got here, UPS called me because they needed another form filled out and signed by me. On that, I just put the same thing.

No problems, no customs charges.

By any chance do you know what customs forms you used? I can't figure out which is the best to use

Whichever company you use to send it, they should be able to give you the forms.

The person who sent it filled out something (not sure what, but guessing it was a US form) and I filled out form C3 when it got in country and they needed a UK form to determine the liability.

I used to work with FedEx.  Chances are, the original form that was filled out in the US was a simple invoice.  FedEx (and I'm sure UPS as well) has a stock form that can be used on the spot if the shipper does not have one ready.  The form must be in triplicate and state the shipper's address and contact info, as well as the recipient's.  Other than that, it needs to list everything being shipped, in as much detail as possible (mainly answering the questions of 'what', 'where made',* and 'how much').  Every company that ships internationally has some kind of publication which indexed by country which items would be accepted by customs and what special documentation was needed (FedEx had a monthly book about 2000 pages thick for this).  As far as VAT, that sounds like something the recipient needs to fill out when the item arrives.

*N.B.: Some countries have really "interesting" import laws, such as prohibiting things made by criminals in Algiers, or wood made in Libya.