Why is sulfamic acid, not sulfuric, used for estimating naoh concentration?

The reaction of NaOH and HCl is as follows: NaOH+HCl⇒NaCl+H2O.  So the ratio between the two reactants is NaOH:HCl=1:1.According to the question, the moles of NaOH needed to neutralize the acid is 0.243M*0.04633L=0.01126mole. Because is the above ratio (1:1), the moles of acid that are being neutralized is also 0.01126mole.  So the concentration of the acid is 0.01126mole/0.010L = 1.126 M.