‘May’ & ‘must’ (again)

CSR v ACN 005 057 349 Pty Ltd [2017] HCA 6

If an official discretion is subject to preconditions, there may be a duty to act once they are satisfied10.  That was not what happened in this case, however.  An Act said the revenue may amend errors in land tax assessments (such as overpayments).  The problem was that another provision11 placed a three year time limit on refunding overpaid tax (which had expired). 

The High Court said (at [63-64]) the revenue had no obligation to amend assessments or refund tax overpaid because the taxpayer was statute barred by the three year limit12iTip – look closely at the wider statutory framework before deciding that your discretionary ‘may’ becomes a mandatory ‘must’.

This case is from Episode 22 of interpretationNOW!


10  Episode 12 – When ‘may’ means ‘must’.

11  s 90AA of the Land Tax Act 1958 (Vic).

12  cf Royal Insurance (1994) 182 CLR 51 (at [65, 87]).