VAT for EU artist for one sale in UK

I'm an artist based in the EU, and I'm taking part in a one-off exhibition (with a possible sale) at a London art gallery. The gallery says I need to register for UK VAT and account for UK VAT with H.M. Revenue & Customs. My painting is priced at £900, but the gallery takes a commission + VAT, so I'd only receive £410 if it sells. There's also a chance it won't sell, and I'll just get the painting back. My questions are: Do I really have to register for UK VAT? If do have to register, even if this is the only sale I make, and there's nothing further planned, would I still need to report to HMRC every three months? I've tried reading all the information on gov.uk about VAT, but it's a bit confusing. Thank you.

Place of supply of goods is where they are at time of sale. The goods (the art) are in the UK at time the sale takes place at the exhibition. So this suggests that you own goods in the UK and at the time you sell those goods, tey (the goods) are in the UK. The VAT registration threshold is £90,000 but only for UK resident seller (a UK based Ltd or a UK based sole trader), but for a non-UK seller, the VAT threshold is Nil. This is the exact same for a UK artist selling at a one-off event in the EU, the place of supply would be in the EU, the seller would not be EU resident and the various EU VAT thresholds are irrelevant, the non-EU resident registers from their first sale, regardless of value. So the gallery are correct to suggest a UK VAT registration is required. If this was a one-off sale of art then once you declare your sale to HMRC on your first VAT return, you could then choose to de-register for VAT as you'd no longer be making anymore sales in the UK, or you might want to attend other UK exhibitions and auctions and so it might be worth keeping your VAT registration and you would file a Nil VAT return each quarter....or you could de-register for VAT once your sale has finished and then you can always re-register for VAT in the future if you have another event to attend in the UK. If the gallery insist on a VAT number before you can show your art then you are bound by the terms set by the gallery, in an ideal world it would be better to only register for VAT once the art has sold, but then the gallery might be of the view that they then would have to wait for your to apply and get a VAT number after the sale, this might take 2-3 weeks to be processed by HMRC and the gallery may not want to have to check in on you and check your VAT status after the sale, again, if the gallery demands VAT registration before art can be shown then that is between you and the gallery.

Hi,
If you are a non established business and you make a sale of goods in the UK then there will be a requirement to register for VAT.
For overseas businesses there is no VAT Registration threshold and so there would be a requirement to register upon the first sale made regardless of the value of this sale. You can see the guidance here:
Non-established taxable persons — basic information
If you are not going to make any further sales in the UK then you can then cancel your VAT number. Please see the guidance below:
Cancel your registration
Thank you.