Yes — and depending on what kind of form it is, you might not need any app at all. iPhones handle PDF forms better than most people expect. The main thing to know upfront is that there are two different types of PDF forms, and they behave very differently on mobile.
Interactive Forms vs. Flat Forms
An interactive PDF form has actual form fields built into it — text boxes, checkboxes, dropdown menus, signature fields. When you open it, you can tap directly into a field and type. A flat form is just a PDF with lines and boxes drawn on the page, but no actual interactive elements underneath. Filling it out requires placing text on top of the visual elements, which is a bit more manual.
Most government forms, official applications, and professionally created business forms are interactive. Documents that were designed in Word and then printed, then scanned, or PDFs created from paper are usually flat.
Using the iPhone's Built-In Tools
For interactive forms, the Files app on iPhone can open PDFs and let you fill in fields directly. Open the PDF in Files, tap a text field, and the keyboard appears. Checkboxes can be tapped to toggle. When you're done, save or share the filled-out version. No additional app needed for basic interactive forms.
Apple's Markup tool (accessible by tapping the pen icon when viewing a PDF in Mail, Files, or Safari) lets you add text, draw, and sign on top of flat forms. It's basic but works for simple situations: tap the text tool, tap where you want to type, and enter your information. For signatures, Markup has a built-in signature capture that lets you sign with your finger or Apple Pencil.
When You Need More Than the Built-In Tools
The built-in iPhone tools cover basic form filling well but have limits. Markup doesn't let you resize or reposition text after you place it without deleting and retyping. It can't handle complex interactive form fields like radio buttons or calculated fields. And saving a signed copy back to the original location while keeping a copy for yourself requires a few extra steps.
For forms that need more precision — legal documents, multi-page applications, forms with signature fields that need to be positioned exactly right — a dedicated PDF Editor handles it better. Browser-based tools like WukongPDF work on iPhone through Safari: open the site, upload the PDF, fill and sign, download the result. No app installation needed.
Signing a PDF Form on iPhone
Signatures on iPhone can be done a few ways. Markup's built-in signature tool lets you draw your signature with a finger, save it, and place it on the document. This works well for informal documents. For anything more official — contracts, legal forms, HR paperwork — a typed signature or a clean image of your handwritten signature placed precisely on the signature line looks more professional.
If you need to sign frequently, it's worth saving a clean version of your signature as an image that you can place quickly. Photograph your signature on white paper with good lighting, crop it tightly, and save it to your Photos app. Most PDF tools let you upload and place it as an image in seconds.
Saving and Sharing the Completed Form
After filling out a form on iPhone, saving and sharing is straightforward. From Markup or Files, tap the share icon and choose how to send it — email, AirDrop, iMessage, or save to Files or iCloud. Make sure you're saving a copy of the completed form, not just the original unfilled version.
One thing to verify before sending: open the completed PDF and scroll through it to confirm all your entries look right and nothing shifted. On some forms, text placed via Markup can look slightly off depending on the font rendering of the viewer on the other end. A quick visual check before sending saves the awkwardness of sending a form with errors.
What iPhone Can't Do With PDF Forms
A few things are genuinely difficult on iPhone regardless of the tool. Creating a new fillable PDF form from scratch — adding interactive fields to a document — is a desktop task. Editing the actual content or structure of a form (changing the questions, not just filling in answers) requires a desktop PDF editor. And forms that use JavaScript for calculated fields or conditional logic may not work correctly in mobile browsers.
For filling out and signing forms you've received, though, iPhone handles most situations well. Between the built-in Files and Markup tools and browser-based options, you rarely need to wait until you're at a computer.