“The approach to be taken on applications for postponements of tax under s55 of TMA 1970 was considered by the Court of Appeal in Williams (HM Inspector of Taxes) v PumahavenLtd 75 TC 300 and in Parikh v Curry 52 TC 366. From those cases we have derived the following principles: (1) In order to succeed with their application [the appellants] do not need to prove all relevant facts or succeed in all legal arguments which will have to be proved or established at the hearing of the substantive appeal. They simply have to show ‘reasonable grounds’ for believing that they are overcharged by the assessments in question. (2) To be ‘reasonable’, the grounds must not be ‘fanciful, imaginary or contrived’ and must be ‘agreeable to reason, not irrational, absurd or ridiculous’. (3) There must be some firm basis, in the form of evidence, for the grounds put forward.” (1) In order to succeed with their application [the appellants] do not need to prove all relevant facts or succeed in all legal arguments which will have to be proved or established at the hearing of the substantive appeal. They simply have to show ‘reasonable grounds’ for believing that they are overcharged by the assessments in question. (2) To be ‘reasonable’, the grounds must not be ‘fanciful, imaginary or contrived’ and must be ‘agreeable to reason, not irrational, absurd or ridiculous’. (3) There must be some firm basis, in the form of evidence, for the grounds put forward.”