The postponement involves extending the period within which the taxpayer may validly make payment of the tax debt.
Payment instalments are a form of postponement, in addition to the deferred payment it is the division or distribution of the tax debt in instalments or staggered maturities.
In theory they are deferrable or fractional, at the request of the taxpayer and prior administrative authorization, all tax debts whose ownership corresponds to Public Finance (regardless of that they are in voluntary or executive pay period).
Nevertheless, tax liabilities arising from withholding personal income tax or corporate tax cannot, as a rule is subject to postponement or subdivision. Only when maintenance is potentially affected of productive capacity and economic employment level activity of the debtor, can be very exceptionally be postponed or split withholding debts.
Tax debts which are collected by using stamped paper in no case are subjected to postponement or fractionation.