The Income Tax Department carries out preliminary assessments of all the Income-Tax Returns filed by the taxpayers. This preliminary assessment is done under Section 143 (1) of the Income Tax Act, 1961. This intimation is nothing but a comparison between the details provided by the taxpayers and the calculation done by the assessing officer. It is completely a computerised and automatic process which is done by the Centralised Processing Center (CPC), Bengaluru, without any human intervention. According to Income Tax rules, the intimation under section 143 (1) has to be sent to the taxpayer within one year from the end of the financial year in which the income tax return is filed.