This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Inheritance Tax Manual

Special valuation matters: machinery and plant

The VOA (IHTM23002) may be asked for a valuation of machinery and plant (other than in going concern (IHTM23179) cases where it will be taken into account by him in that valuation) provided that there are grounds for doubting the value put forward by the taxpayer & the assets are not covered by 100% business relief.

When making such a request, send the VOA an itemised schedule of the assets to be valued.