As per ICSI FAQ- 54
In terms of section 135(5), the board of every company, to which section 135 is applicable, shall ensure that the company spends, in every financial year, at least 2% of the average net profits of the company made during the three preceding year.
There is no provision of spreading over the expenditure incurred in a particular year over the next few years. The words used here is at least. Therefore any
Expenditure over 2% could be considered as voluntary higher spend. However, in case, a company does not want to spend the 2% in the subsequent year on account of it having spent a higher amount in the previous year, the Board’s report may state so.