6 Step Guide To Automating Client Onboarding for Agencies

6 step guide to automating client onboarding for agencies

Omid G Jul 03, 2025

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There’s no better feeling than signing your first client.

But that feeling usually comes with a side of anxiety too.

“What if I mess this up?”
“What if I come across as an imposter?”

Totally valid. I’ve been there. I had those exact thoughts when I signed my first marketing client over three years ago.

The truth is, doing great work is only part of the job. The other part, the one nobody really talks about, is how you bring clients into your business. Because the way you handle onboarding sets the tone for everything that follows.

In this guide, I’m going to walk you through how to build a smooth, professional client onboarding experience using the exact process I’ve refined while running my agency. It’ll help you look polished, stay organized, and actually make your clients excited to work with you.

Let’s get into it!

What is the agency client onboarding process?

The agency client onboarding process is a series of steps you take when you’re bringing a new client into your business and setting up the foundation for the work you’re about to do together.

It includes everything from sending over a welcome message, collecting key info, signing contracts, and setting up billing. But the best onboarding experiences actually start before the client kicks off. It’s all in how you prep.

Do you have a repeatable system that reduces busy work?
Do you have forms ready to go?
Do clients know exactly what to expect from the start?

The better you plan, the better the first impression will be. And that impression can be the difference between a one-off project and a long-term client.

In the next section, I’ll break down exactly how to set up an easily repeatable onboarding process using tools like client portals, automations, and templates, so everything feels smooth and scalable from day one.

6 steps to the marketing agency client onboarding process

Here’s a six-step process to automate your client onboarding:

Let’s go over each of these.

Automate with client portal software

The first step to any modern marketing agency onboarding process is to use software and tools to help you build a remarkable client experience.

I'm going to admit, building a successful service business is hard. It's a lot more than just mastering a skill and being able to sell that skill to businesses. When you start a marketing agency, you are really going into the business of relationships.

The way I've personally kept clients for years at a time, outside of just driving performance results, has come from creating a human connection with my clients. And it's why I always recommend every marketing agency first focus on their client experience.

Once you’ve found a client portal tool and set it up, the next step is to prepare it for a smooth and repeatable onboarding process. Once a client logs in or signs up to their portal for the first time, the first thing that they should see is a welcome message. Let's get into that.

Create an automated welcome message

Alright, your client just signed in for the first time. This is your moment to make a strong first impression.

One of the most underrated parts of the onboarding process is the welcome message. It sounds simple, but it sets the tone for the entire relationship. Instead of leaving your client wondering what to do next, you can use this message to give them direction, clarity, and confidence in your process.

Inside Assembly, you can set this up using the Messages App, which lets you send both custom and automated messages to clients. I use it to create a personalized welcome message that goes out the second a new client account is created.

Set up intake forms based on triggers

Once your welcome message is ready, the next step is to collect the info you need from your client to get started.

This is where intake forms come in. A client intake form is basically a form you send to your client to collect all the important details about their business, goals, preferences, and anything else you need to do your job well.

The goal here isn’t to overwhelm your client with a 50-question form. Keep it focused. Ask for just enough to get started with clarity, and save the deeper stuff for later once the relationship builds.

Invite your client to their dedicated portal

Now that your intake form is set up and ready to go, it’s time to invite your client into their portal.

You can either manually create a client profile, or you can send your client a sign-up link so they can create their own account.

Get your contracts e-signed

Once your client is in the portal and has filled out their intake form, it’s time to make things official.

Assembly makes this part really easy. You can upload your contract directly into the Contracts App and send it out for e-signature without ever leaving the platform.

Set up payments or subscriptions

The final piece of onboarding is getting your payment system in place. Whether you’re charging a flat monthly retainer, doing project-based work, or using a hybrid model, you want billing to feel easy and seamless for both you and your client.

Inside Assembly, you can use the Billing App to create one-time invoices or set up recurring subscriptions. Your client gets notified, they pay directly in the portal, and you get paid without needing to follow up.

Modern marketing agencies run on Assembly

If you made it this far, congrats. You’re far ahead than most agency owners. The marketing agencies that grow fast and keep clients for the long run are the ones that get serious about their systems. They make the entire client experience feel smooth, organized, and human from day one.

That’s exactly what Assembly helps you do. From intake forms and welcome messages to contracts, payments, and more, Assembly gives you everything you need to build a repeatable onboarding system that feels like an extension of your brand.