When Should I Bill Clients for Work?

By Jack Whitehead

3 February 2026

Knowing when and how to invoice a client can affect both cash flow and your relationship with them. You want to get paid. You also want your client to consider working with you again one day.

The invoicing process can vary depending on your project, the industry you work in, and even the relationship you have with your client, so there’s no one-size-fits-all answer. Which is why we wrote an article about it.

Billing once work is completed

Billing once the work is done can be a great way to keep things simple and straightforward. Clients pay once everything’s finished and they’re happy with the final product, which feels fair for both sides.

It can also build trust, as the client knows they’re not paying until the work is actually delivered.

But on the flip side, it can put pressure on your cash flow since you won’t see any money until the project is wrapped up – which can be a particular pinch point if you’re paying for anything up front before re-charging the client.

You’ll need to stay on top of your budgeting and record-keeping to make sure nothing slips through the cracks. It’s definitely a balance – but when it works, it can work well.

Tips for billing on completion

If you use this method, make sure you’re very clear about the scope of the project upfront, such as with a written agreement. Always include payment terms on your invoice!

Asking for a deposit before getting started

Asking for an initial deposit before work kicks off is fairly common in some industries. Depending on the nature of your business you might ask for a percentage of the total fee or for the cost of any materials up-front.

This helps reduce the risk of you being stuck with 250 personalised teaspoons that you can’t sell to someone else, for example.

What are milestone payments?

As a longer project moves along, it’s often a good idea to break things into phases and invoice after each major milestone. For example, say you’re designing a website.

You might send an invoice after the wireframe is done, then another one after the design gets approved, and then a final one when the completed site is ready to go live. The last payment typically comes after the project is totally finished and the client has signed off on everything.

What are the challenges with milestone payments?

Sometimes clients might be a bit hesitant about milestone payments, especially if they’re used to paying everything at the end. If you explain that breaking the payments up helps ensure quality and protects both sides, they’ll usually understand.

It’s also really important to keep track of those milestones and make sure you’re both on the same page about what needs to be done and when. Clear communication and documentation like a written quote are key to making sure everything goes smoothly for both you and your client.

Retainer agreements for ongoing work

Retainer payments can be amazing for your cash flow. Since clients pay you upfront for a set amount of work over a certain period, it makes income more predictable so budgeting is easier.

You don’t have to worry as much about those gaps between projects or chasing down payments because you’re already set for the next few months. Plus it allows you to focus more on the work itself instead of stressing about when you’ll next get paid.

Do retainer agreements have any downsides?

Retainer agreements can be awesome, but they do come with a couple of challenges. For one, clients might expect you to prioritise their work, so you may need to manage both their expectations and your time!

Make sure terms are completely clear from the start. Otherwise clients might start expecting more work than what was originally agreed.

Tips for retainer agreements

Agree what's included and the hours or services covered in advance. Revisit the agreement every so often to make sure it still meets both your needs and your client’s.

How does each one affect cash flow?

The timing of your invoices directly impacts your business’s cash flow. For example, if you bill only once a project is completed, you may face delays in receiving payments, which can affect your ability to cover your expenses. Milestone payments, on the other hand, can keep money flowing steadily, helping you manage your business’s financial needs.

In a nutshell, here’s how different billing methods can affect cash flow:

  • Billing on completion: You’ll likely have some gaps in income, especially with long-term projects
  • Milestone payments: Steady payments help maintain a consistent cash flow, but they do depend on hitting those milestones on time
  • Retainers: The most predictable cash flow option, as payments come regularly, even if the amount is smaller than a one-time fee

Balancing different types of billing methods can help smooth out cash flow fluctuations. For example, you could do milestone payments for larger projects and offer retainer agreements for ongoing work.

How should I take payment?

Once you’ve decided when to bill your clients, the next question is how should you take payment? There are a few different methods to consider, such as:

  • Bank transfers: A reliable option but can take a few days to process
  • Online payment platforms: Tools like PayPal and Stripe make it easy for clients to pay quickly, but watch out for transaction fees
  • Cheques: Sometimes clients still prefer paying by cheque, but this method can be slow and there’s the risk of the cheque bouncing
  • Credit cards: Some clients may like using credit cards but be aware some payment gateways charge fees for credit card transactions

Offering a variety of payment methods to meet your clients’ preferences can encourage them to pay more quickly, but always keep fees in mind.

How should I follow up on overdue payments?

Even with clear payment terms and invoices, there are always going to be times when a client is late with payment. It can be hard on your cash flow – and on your sense of humour.

It’s best not to wait too long before sending a friendly reminder about overdue invoices – the sooner, the better. Using an automated system can help a lot too. It takes the pressure off you, and makes sure you don’t forget (or spend time doing it manually).

And, no matter what, always stay professional in your communication. If payments are still overdue after a few reminders, you might need to get more serious and introduce late fees or collection actions. Telling a customer their cat is ugly is less likely to get results.

Learn more about using Pandle to make business accounting easier. Create an account today and decide what to do with all the extra time you get back.

Jack Whitehead

A degree in Astrophysics means I have a head for numbers! Outside of Pandle HQ you'll find me writing music (and spending too much money on guitars).

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