This guide was taken from https://www.igeeksblog.com/how-to-convert-photos-to-pdf-on-iphone-ipad/

1. How to convert a picture to PDF on iPhone using Printer Options

  1. Open Photos on your iPhone and tap Albums. Now, tap Select and choose one or multiple images.
  2. Tap Share.
  3. Choose Print from the Share Sheet.
     
    tap on select choose photos tap on share and then tap on print in photos app on iphone
  4. Using two fingers on the photo preview, pinch outwards to save the photo as a PDF.
     
    pinch out thumbnail tap on share and select option to convert photo to pdf on iphone

2. Select Books on the Share Sheet to turn a picture into a PDF

  1. Select the photos and tap Share.
  2. Tap Books on the Share Sheet. Swipe horizontally on the row of app icons, if needed.
     
    choose photos tap on share and then tap on books app on iphone
  3. The photos will automatically convert into a PDF file and open in Books. It will be saved there.
  4. Tap the screen and then tap the back arrow to go back.
  5. Next, tap More (three dots).
     
    tap on back arrow tap on three dots in books app on iphone

You can learn more about Books in our full guide.

3. Save photos as PDF on iPhone and iPad using the Files app

Files lets you quickly create PDFs. However, the photo must be saved under Files. So, if you already have images here, continue with the following steps. If they are in Drive, Dropbox, One Drive, etc. you can see how to enable these third-party cloud services inside Files.

Or, to copy the pictures from Photos to Files: Select the images inside Photos → tap Share button → Save to Files.

choose images tap on share and then tap on save to files in photos app on iphone

Once that’s out of the way, here are the steps to create a PDF from Photos on the iPhone.

  1. Open Files and locate the image.
  2. To convert a single image into a PDF: Long press on the image and choose Create PDF.
     
    long press on image and tap on create pdf in files app on iphone
  3. To convert several images into PDF: Tap More (three dots inside a circle) from the top right and tap on Select.
     
    tap on three dots and then tap on select in files app on iphone
  4. Now, tap multiple photos. Once done, tap More from the bottom right and choose Create PDF.
     
    select files tap on three dots and then tap on create pdf on iphone

Files will make a PDF out of those images. It will get saved in the same location as the original pictures. You can see our full guide on using Files to copy, move, or share this PDF.