New Zealand Trusts holding UK shares

We have a couple of situations where New Zealand trusts directly hold
investment portfolios that include UK listed equities. The portfolios
are actively managed by investment management firms so the extent of UK
equities changes over time. In all cases, the trustees and the children
are solely New Zealand residents. In some cases, the investment
management firms are based in New Zealand, in others they are based in
the UK.

Does the ownership of UK listed shares trigger an obligation to register
the trust with HMRC? My understanding is that this would be the case
if any of the following scenarios apply due to the UK tax that would arise:

  1. The value of the UK equities exceeds £325,000 (for each settlor)
    at the 10 year anniversary of the trust

  2. Further UK equities are purchased

I would be grateful for any guidance from members. The new New Zealand
domestic trust reporting obligations that came into effect last year
will significantly increase the extent of information that is captured
(and evaluated) by our Inland Revenue.

Lee Harris

Martelli McKegg, New Zealand