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

HMRC internal manual

International Manual

DT Agreements: Qatar - Income from a UK source paid to a resident of Qatar

The permanent establishment provisions of Article 5 include references to a building site or construction or assembly project. This provides that where such a site continues for a period of more than six months in any twelve month period commencing or ending in the tax year concerned it will constitute a permanent establishment.