HMRC Admin 13 Response

The general rule is that a company which is not resident in the UK has to pay UK Corporation Tax only if:

• it has a permanent establishment in the UK
• the economic activity that generates its profits is carried out in the UK

Further guidance on company residence can be found at INTM120210 - Company residence: guidance originally published in the International Tax Handbook - HMRC internal manual

As previously advised, the general rule is interest paid is tax deductible and interest received is taxable by reference to when it is accrued, rather when it is paid or received.
Special rules apply where there is a delay in paying the interest.
You can find HMRC guidance on this topic at CFM35800 - Loan relationships: connected parties: late interest: Contents - HMRC internal manual