Processing of tax collected at source requires correction, computation, adjustment and intimation of payable sums or refunds. Processing of a collector's statement or correction requires computing sums collectible after correcting arithmetical errors and identifying incorrect claims apparent from the statement, computing interest on computed sums, calculating any statutory fee, adjusting prior tax, interest or fee payments against the liability, generating an intimation specifying net payable sum or refund due, and granting refunds so determined; intimations must be sent within one year from the end of the financial year in which the statement was filed, and a centralised processing scheme may be made to expedite determinations.