How to Merge PDF Files in the Correct Order

Before you merge

• Every source is the final version, with no duplicate drafts.
• All the files are selected in one batch.
• The file strips are dragged into the intended order.
• The last page of each file leads into the first page of the next.
• Any password-protected file has been unlocked.
• The merged PDF has been opened and scrolled through before sending.

Use a sort rule that survives file pickers

Write dates as year-month-day when chronology matters, and number parts with leading zeros (01, 02, 10) so alphabetical order still works. Do not trust the order files were selected in. File pickers and mobile share sheets can return them differently from the order you tapped.

Fix pages after merging, not before

If one source scan is upside down, merge first and rotate only the affected pages. If the merged file goes over a size limit, compress the completed bundle so you measure the file you will actually submit.