You can scan documents on an iPhone using the built‑in Notes or Files apps, and the result is usually saved as a high‑quality PDF ready to share or print.

Notes app method (fastest)

  • Open the Notes app and create a new note, or open an existing one.
  • Tap inside the note so the keyboard appears, then tap the camera icon above the keyboard and choose Scan Documents.
  • Point your iPhone at the paper; it will usually auto‑detect and capture the page in Auto mode, or you can tap the shutter button to scan manually.
  • Drag the corners to adjust the crop if needed, then tap Keep Scan ; repeat for more pages, then tap Save to add the scan to the note.
  • Tap the share button in the note to send the scan as a PDF via Mail, Messages, or save it to Files or iCloud.

Files app method (great for PDFs)

  • Open the Files app and go to the folder where you want the scan saved.
  • Tap the three‑dot menu (More button) in the top‑right and select Scan Documents.
  • Aim the camera at your document; in Auto mode it captures automatically, or tap the shutter/volume button to scan. Adjust corners if needed and tap Keep Scan.
  • Scan additional pages if you want a multi‑page PDF, then tap Save ; your scan is stored as a PDF right in that folder and syncs via iCloud if enabled.

Quick tips and “latest” tricks

  • Modern iOS versions let you tweak filters like color, grayscale, or black & white to make text sharper and easier to read.
  • You can add signatures or markup to a scanned PDF from the share sheet using the Markup tools before sending.
  • Many recent how‑to videos (2024–2025) show that this works on current models like iPhone 14, 15, and 16 series with iOS 18, so it’s a reliable built‑in alternative to third‑party scanner apps.

TL;DR:
Use Notes → camera → Scan Documents for quick scans inside a note, or Files → More (…) → Scan Documents to create a PDF directly in a folder you choose.

Information gathered from public forums or data available on the internet and portrayed here.