Exemption from paying on moving stuff you already own?

I'm going to ship some stuff from the US to the UK with a value probably of a few thousand $$$ in a few boxes.
I was told a while back by someone that if you're moving into the UK from somewhere else you can get an exemption off the crazy fees they try to throw at you for stuff you already own. How do I go about doing this? I don't want my stuff getting stuck at customs and paying ridiculous $$$ just to keep my stuff.

I didn't do it, but I think you're referring to Transfer of Residence, or TOR.  Try searching the forums for that for some firsthand experiences.  Or for the official word, go here: https://www.gov.uk/government/publications/application-for-transfer-of-residence-tor-relief-tor01

"You must also:
•
 
have lived outside the EU for at least the last 12 consecutive months"

Really? 

Guess I'm packing the valuables in my on-plane luggage. I've only been out of the UK for like 8 months come my moving.

There's a 390 pound limit on what you can even carry in your luggage.
Am I just screwed? Guess I'll call the HMRC and find out. I don't want to pay freakin' a ridiculous amount of $$$ for the stuff I already own and have owned for years.

EDIT: Okay, nevermind. I called and they said the form isn't as strict as most government forms and that my situation should be no problem. This is the oddest form I've filled out for a government body.

Okay, I've got my exemption and number. Now what do I do with it when it pertains to the stuff I'm taking on the plane? I'm taking several thousand $$$ worth of things on the plane. Is there a customs form that has an area where I can show this number?

I know that I can give this number to shippers but what about the stuff I bring with me? I'm bringing with me as much as I can fit in 3 suitcases on the plane. I don't know how to both declare it and show this number they gave me and I don't know what form to use. I can't find it on the government website.

I'm sorry, Superman.  I don't know the answers to any of your questions as this stuff didn't really apply to me (I came over with very few possessions).  I wish we could get the attention of others who know.  Let me go find which forum I've seen these issues in.  Maybe I can send someone your way.

I had mostly clothes in my bags, but did have a MacBook, iPad and other electronic devices. I simply didn't stop at the  customs area in Heathrow.

I can't offer any advice as TOR didn't exist when I moved over in 2014. I'll have to use it when I finally get around to bringing my 6 boxes of items over. Have you looked on any of the other threads about TOR? I think a lot of them may be in the Visa section and I don't go there.

I've been reading lots of threads here and other places. I've still not found the answer.
It seems straightforward if I'm dealing with a shipping company. But if I'm dealing with simply bringing much of my stuff over in my suitcases (a few computers, some expensive'ish collections of things, video games, etc) and I've not found the answer.

Like I'm wondering if I'm missing a form somewhere, or if there's a place I'll input my exemption number when I get off the plane and they give me that little piece of paper they make me do every time. Or if I just declare nothing of value and see if they don't care?

They might find it ODD when they see my suitcase has a PS4, Switch, video games, a few computers, and some Lego lol. I'd rather bring them with me on the plane so I don't have to ship too much stuff and wait a good while for them to come in on a barge.

They only need a ToR for shipped items.  You don't need it for items in your possession when you travel.

Do I not need to declare the stuff or the value of the stuff? There's that 390 pound limit. Does it not count if it's personal items?