Printing control apparatus method for controlling printing control apparatus and storage medium

A printing control apparatus including a reading unit for reading an image on a document and generating image data and a printing unit for printing the image performs a copy job using the reading unit and the printing unit, the printing control apparatus comprising:

• a conveying unit for conveying a document set on a document setting unit to the reading unit;
• a first detection unit for detecting a size of the document set on the document setting unit before the conveying unit starts to convey the document;
• a second detection unit for detecting the size of the document after the conveying unit starts to convey the document;
• and
• a control unit for performing the copy job based on the size of the document detected by the first detection unit in a case where the printing unit starts to print the image data before the reading unit finishes generating image data for one page and performing the copy job based on the size of the document detected by the second detection unit in a case where the printing unit starts to print the image data after the reading unit finishes generating image data for at least one page.