Loan Charge – what is a loan?

HMRC continue to pursue taxpayers who have received loans back from either in lieu of earnings of typically a contractor or back from an Employee Benefit Trust (EBT).  The Loan Charge was effective from 30 September 2020 by which time HMRC were to be notified of all such loans and tax paid on them under the Disguised Remuneration rules.  But for some, the issue has become what is a loan?