I thought it was worth copying and pasting the relevant text (regarding Lump-Sum payments) from the HMRC post. This is below.
The relevant point is that I have seem much advice suggesting that Article 17(2) of the Tax Treaty which many quote as a reason to only tax distributions of Lump sums from a US IRA / 401(k) in the USA, and by extension claim exemption from UK tax. This HMRC interpretation clearly disagrees with this position as explained in the text.
I'd be interesting in any counter opinions as it is something I'm dealing with at the moment in my 22/23 UK tax return, and in my planning for closing out the 2023 US Tax year.
Cheers
G
Lump Sum Payments
There is no legislative definition of a lump sum but HMRC regards these as being any non-periodic payment of a pension, that is, any non-regular payment that decreases the value of the remaining pension pot after such payment is made. For example, the first (IRA) withdrawal is taken in year 1, the next withdrawal was made in year 5, and another withdrawal in year 7, such payments will not be regarded as periodic and will be treated as lump sums under the UK/USA Double Taxation Agreement (DTA). Whereas any amount withdrawn in set, periodic, frequent intervals, that is weekly, monthly, annually and so on would not be a lump sum, but rather periodic payments.
Article 17(2) of the UK/USA DTA provides the US with the right to tax any lump sum payment which is made from a US sourced pension scheme, including IRAs. However, the UK is also permitted to tax the same lump sum payment(s), which is in accordance with Article 1(4) of the DTA, both Article 17(2) and Article 1(4) are outlined below and, when read from the perspective of a UK resident, state:
Article 17(2) - Notwithstanding the provisions of paragraph 1 of this Article, a lump-sum payment derived from a pension scheme established in a Contracting State [USA] and beneficially owned by a resident of the other Contracting State [UK] shall be taxable only in the first-mentioned State [USA].
Article 1(4) - Notwithstanding any provision of this Convention except paragraph 5 of this Article, a Contracting State [UK and/or USA] may tax its residents, and by reason of citizenship may tax its citizens, as if this Convention had not come into effect.
A UK resident, Article 1(4) above permits the UK to tax any US sourced lump sum payment received, as if Article 17(2) of the DTA was not in force or applicable, Article 1(4) effectively ‘overrides’ the provision at Article 17(2), and the consequence is that both the UK and USA can tax any lump sum payment received from a US sourced pension scheme.
In these situations, double taxation will occur since both the UK and the USA can tax the same income. However, that double taxation will be eliminated in accordance with Article 24(4)(a) of the DTA which requires the UK, as the country of residence, to provide Foreign Tax Credit Relief (FTCR) to offset the US tax correctly paid against the UK tax charged on the same the IRA withdrawal.