Is pocket veto allowed?
As a general rule, no.
Under the Constitution, the President does not have the so-called pocket-veto power, i.e., disapproval of a bill by inaction on his part. The failure of the President to communicate his veto of any bill represented to him within 30 days after the receipt thereof automatically causes the bill to become a law.
This rule corrects the Presidential practice under the 1935 Constitution of releasing veto messages long after he should have acted on the bill. It also avoids uncertainty as to what new laws are in force.
When is it allowed?
The exception is provided in paragraph (2), Section 27 of Article 6 of the 1987 Constitution which grants the President power to veto any particular item or items in an appropriation, revenue or tariff bill. The veto in such case shall not affect the item or items to which he does not object.