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Auto-Fill and Submit PDF Forms via REST API for HR Onboarding, Insurance, and Finance Workflows

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Tired of manually handling form data? Learn how I automated HR and insurance workflows using imPDF Cloud PDF REST API and never looked back.

Every form felt like a tiny monster

I’ll be real with you.

Every time I got a batch of new hire forms, I’d groan. Whether it was HR onboarding packets, client insurance documents, or finance paperworkPDFs always slowed me down.

Manually opening forms, typing in the same info over and over, checking if the right fields were filled… it’s soul-crushing.

In one onboarding sprint, I wasted an entire afternoon just filling PDFs.

Then I thought: There’s no way this still has to be manual in 2025.

So, I started digging.

And that’s when I found imPDF Cloud PDF REST API for Developers.

This API changed everything for my workflows

Let me break it down for you.

The imPDF Cloud PDF REST API is a RESTful API that plugs right into your app, scripts, or backend workflows. No heavy lifting. No clunky UI. Just clean endpoints that let you auto-fill, export, flatten, split, merge, and even secure PDF forms.

I used it in a real HR onboarding process.

Here’s what I had:

• A dynamic XFA-based employment form from a third-party payroll system.

• New hire data coming from an internal tool via JSON.

• And a ticking clock.

What I needed was:

• Auto-fill the PDF form with JSON data.

• Flatten the form so it’s not editable afterward.

• Email it to HRall in one automated flow.

imPDF made it happen in less than 30 minutes.

Why this REST API is worth using

Here are a few of the key things I testedand loved.

1. PDF Form Import API

Use case: I uploaded a dynamic XFA form and passed in structured JSON. Boomit populated every field accurately.

json
{

"firstName": "Liam",

"lastName": "Gray",

"startDate": "2025-06-10",

"email": "liam.gray@company.com"

}

All that manual copy-pasting I used to do? Gone.

The endpoint is rock solid and handled nested structures with no sweat.

2. Flatten Forms API

Once the fields were filled in, I didn’t want the HR team (or worse, the new hire) accidentally editing the form.

So I hit it with the flattening endpoint. It locked the data into the pagelike printing it to paperbut still fully digital.

Super useful for:

• Insurance claims

• Tax documents

• Signed contracts

3. Merge PDFs API

In HR workflows, forms aren’t alone. You’ve got NDAs, policy sheets, tax forms.

I was able to merge these into one clean file using the Merge API. Perfect for digital delivery and archiving.

This API saved me hoursnot an exaggeration. And in finance teams I’ve worked with, it would shave days off of month-end closeouts.

How does it stack up against the usual suspects?

I tried Adobe Acrobat’s automation tools. Yeah, they existbut they’re heavy, expensive, and require a UI layer.

Tried open-source PDF libraries? They work, but the setup is a pain and maintaining them is worse.

With imPDF, it was:

• Just REST endpoints

• No server hosting needed

• Supports XFA and AcroForms

• Language-agnostic (Python, JS, PHPyou name it)

• Perfect for low-code tools like Zapier or Power Automate too

You don’t need a full-stack dev team to plug this into your system.

Who’s this API for?

Honestly, if you’re:

• An HR team managing dozens of onboarding forms weekly

• An insurance agency processing client applications

• A finance back office converting invoice templates to reports

• A developer building a form-based SaaS product

this is for you.

The use cases are everywhere:

• Batch filling employee details

• Auto-submitting digital insurance forms

• Importing form data into CRM systems

• Flattening and securing tax PDFs

• Exporting data from PDFs to run analytics

If your workflow touches PDFs, this saves you time.

What surprised me the most

API Lab. This is where it clicked for me.

I tested everything in their API Lab before writing a line of code. Uploaded the form, plugged in mock data, tweaked options, ran the processand the result downloaded instantly.

Then I copied the generated code and pasted it into my workflow.

Done.

No endless debugging. No SDK rabbit holes. Just fast iteration.

What it solved for me

I went from:

• Wasting hours in Adobe

• Tracking dozens of form versions in email threads

• Accidentally editing the wrong template

• Missing fields that never got filled

To:

• Running a single API call with JSON

• Flattening and locking forms on the fly

• Generating clean, final PDFs in seconds

• Automating everything in a few lines of code

Real talk: should you try it?

Absolutely.

If you’ve got workflows where forms, automation, and PDFs intersect, this tool is a no-brainer.

Click here to try it out for yourself: https://impdf.com/
Start your free trial now and boost your productivity.

imPDF Custom Development Services (Rewritten)

Need something more tailored?

imPDF doesn’t just provide out-of-the-box API toolsthey also build custom solutions to fit your exact needs.

Whether you’re working on Windows, macOS, Linux, iOS, or Android, they can develop specialised PDF processing systems for your environment.

Their team has deep expertise in:

• Building virtual printer drivers for creating PDFs and capturing print jobs

• Developing tools for extracting, editing, and converting document formats like PDF, PostScript, PCL, PRN, and Office files

• Creating advanced OCR and table extraction systems for scanned documents

• Building secure digital document workflows with encryption, watermarking, DRM, and digital signatures

• Developing tools with Windows API hooks and system-level integrations

They also offer cloud-based solutions, image processing engines, and AI-powered document analysis systems.

Got something specific in mind?

Reach out here: http://support.verypdf.com/

FAQs

Q1: Can I fill out a dynamic XFA form using imPDF REST API?

Yes. imPDF supports both static and dynamic XFA forms, as well as standard AcroForms.

Q2: How secure is this for handling sensitive documents?

Very secure. You can encrypt files, add access restrictions, and redact sensitive content before delivery.

Q3: Can I automate sending the filled PDF to email?

While imPDF focuses on PDF generation, you can easily combine it with a script or automation tool (like Zapier or Make) to email files after processing.

Q4: What programming languages does the REST API support?

Any that can make HTTP requestsPython, JavaScript, PHP, C#, Java, and even low-code platforms.

Q5: Can I try the API before committing to it?

Yes. imPDF offers an API Lab where you can test features for free before integrating anything.

Tags / Keywords

• auto-fill PDF forms REST API

• automate HR onboarding forms

• fill XFA forms programmatically

• flatten PDF forms API

• insurance PDF form automation

• convert form data to PDF

• dynamic PDF workflow automation

• REST API for form processing