Intimation under 143(1)

Friends

I have received the intimation under section 143(1) from CPC yesterday. AS per ITR there was no refund/no demand but in the intimation there is a demand as the CPC has granted TDS credit of say Rs 180 though in the 26AS the TDS is say Rs 200.

Now I have to file online rectification request but what is astonishing is how could this be. When 26AS is showing TDS credit how could the CPC allow less credit.

Regards,