To combine PDFs, open the first document, add the remaining PDFs, put the pages in the intended order and export a new copy. The important final step is to reopen that copy and check it against your original plan. FileStation’s published merge workflow includes adding PDFs and rearranging page thumbnails. FileStation: Merge PDF
Start with a page plan
Use a simple practice task: a one-page cover, a two-page report and a one-page appendix. Those are illustrative inputs, not a recorded test. Your planned output has four pages. Keep the originals in a separate folder so you can recover from an incorrect selection.
Build and review
Open the first PDF in Merge PDF. Add the other PDFs using the available add/merge control. Look at the thumbnails before exporting: is the cover first, does the report remain in order, and is the appendix last?
Then review the joins between documents. This is where a duplicate cover or missing page can be easy to overlook. Rotate a page only when needed. Export to a new filename that identifies the purpose of the pack.
Reopen the saved copy
Check the page count against your plan. Read the first and last page. Check any links, form fields or navigation you rely on; a visually correct PDF does not prove those features were preserved. The tool’s own notes warn that interactive features may be omitted. FileStation: Merge PDF
Do not overwrite a digitally signed original as part of a casual editing workflow. Ask the document owner for an appropriate editable source or approved process when authenticity matters.
Common mistakes
An unexpected order is a reason to return to the thumbnail view and compare it with the page plan. A missing page is a reason to inspect which inputs were selected. A document that downloads but will not reopen is a failed result, not a successful merge.