Top Margin

I have created a document as a 'home letter head' template. I want the address along the top of the letter to be (relatively)close to the top edge of the sheet - as I can in MS Word. The top margin in Zoho is set to 0% and 'preview' shows the layout to be perfect. But, when I select the PDF for printing, the top margin is too great. How do I rectify this?
patrick.friedma