Originally Posted by UAL Traveler

The limit on the number of page inserts, as told to me by a consular official, is determined by the amount of original visa pages in the passport. Each insert must be attached to two such pages. For example, a 48-page passport has 38 usable pages (pages 8-45, with even page 8 being a left hand page, and odd page 45 being a right-hand page), which allows a total of 19 inserts. So, with essentially 23 usable pages per insert, you can add 437 pages for a total of 475 pages. That's why I get a 48-page pp on renewal.