How to follow up on a past due invoice and email examples for 2025

On average, small business owners spend 14 hours a week tracking down client payments. The key to securing your payment from a past-due invoice is to stay calm and communicate with intention. Our guide equips you with a seven-step strategy, including email templates, to chase down past-due invoices and ensure you get paid on time:

1. Review past-due invoices

2. Set a clear payment schedule

3. Send an overdue invoice notice via email

4. Escalate the follow-up if necessary

5. Personalize the final communication

6. Take legal action

7. Create a schedule to send the past-due invoice emails

Considerations to keep in mind when creating a past-due invoice email

Past-due invoice email templates and examples

Unpaid invoice email escalation

Tips for effective overdue invoice follow-up

How to avoid or reduce past-due invoices

Choose the best payment setup for your business

How long an invoice can be past due?

Legally, the exact timeframe on how late an invoice can be paid depends on local laws and regulations. However, it’s usually up to the business to enforce payment and establish a framework for how they handle past-due invoices.

Adding due dates to an invoice

While there’s not a universal legal requirement, putting a due date on an invoice is considered a best practice because it sets clear expectations for when payment is due and helps prevent late payments. Without a due date, clients may not feel a sense of urgency, which can lead to delays, confusion, and disputes over when payment is actually expected.

Backdating an invoice

Backdating — i.e., issuing an invoice with a date earlier than when it was actually created — an invoice is generally not allowed and is considered fraudulent.

1. Review past-due invoices

An invoice becomes past due when the payment deadline specified on the invoice has passed. Before diving into collection efforts, take a moment to ensure you're working with accurate information.

Double-check the invoice details, like the amount, due date, and payment terms, to confirm everything is correct. This also includes reviewing any previous communication attempts you've made regarding the invoice. Here is a sample past-due invoice for reference:

There are several reasons why a client might be late on payments, including:

Administrative oversight

The invoice may have gotten lost in a crowded inbox, sent to the wrong department, or simply overlooked. This is especially common in larger companies with multiple approval layers.

Cash flow issues

Your client may be facing temporary money problems and could be delaying payments to manage their cash flow. This issue is common for small businesses and startups.

Disputed charges

Your client may have an issue with the bill amount and might think it’s wrong or unexpected. If they don’t agree with a charge, they might postpone payment until the issue is settled.

Confusion over payment terms

Some clients may not understand their due date, late fees, or payment expectations. This usually happens when the contract doesn’t clearly explain these payment terms.

Banking or processing delays

If they sent a check or initiated a transfer, it might just be taking longer than expected to clear.

Intentional delays

Some companies delay payments as a cash flow strategy. While not ethical, it’s a reality in some industries.

Unexpected circumstances

A personal emergency, a sudden business downturn, or staffing problems could be causing the delay.

2. Set a clear payment schedule 

The best way to avoid chasing down late payments is to set clear expectations from the start. When clients know exactly when and how they need to pay, there’s less room for confusion and fewer awkward conversations about overdue invoices.

Be upfront about payment terms

Clearly outline payment deadlines, late fees, and any interest charges in your contract or service agreement. To eliminate confusion, be sure to specify payment methods, such as bank transfers, credit cards, or online payment portals. Also, consider offering incentives for early payments, such as small discounts or perks, to encourage timely transactions.

Break payments into installments

For larger projects or ongoing work, consider splitting payments into smaller chunks instead of billing everything at once. This keeps cash flowing and makes it easier for clients to manage their budgets. A simple structure could look like this:

• Deposit upfront: A percentage of the total amount before you start working.
• Milestone payments: Payments due at specific project stages (e.g., after the first draft, halfway through, etc.).
• Final payment: The remaining balance due upon completion.

3. Send an overdue invoice notice via email

Once you've confirmed the invoice details, it's time for a gentle nudge. Craft a polite email or phone call reminding your client about the outstanding invoice. Be sure to include clear details like the invoice number. Make it easy for them to settle the bill by mentioning your available payment methods, such as online portals, mail-in checks, or credit card payments via a phone call.

So why send an email instead of just waiting it out? For one, it’s a respectful, non-confrontational way to request payment. A well-crafted email keeps the conversation professional without damaging the client relationship. Plus, an email creates a written record of your communication, which is useful if you ever need to escalate things later.

4. Escalate the follow-up if necessary

If your initial attempt doesn't get a response, it's time to take a firmer approach. Send a follow-up email or make a phone call that clearly reiterates the outstanding invoice and the urgency for payment. While maintaining a professional tone, be sure to outline the potential consequences of continued non-payment.

Consequences may include:

• Late fees: These are typically a flat rate or a percentage of the amount owed. Some businesses charge a flat fee of $25 to $50, while others add around a 1.5% monthly late charge to the total owed.
• Accruing interest: If an invoice stays unpaid for too long, you can charge interest on the overdue balance. A standard rate is 1.5% to 3% per month.
• Collection agency involvement: If it’s been months and you’re getting nowhere, you might need to involve a collections agency. Just keep in mind that agencies typically take 25% to 50% of what they recover, so this should be a last resort to emphasize your seriousness.

Continue to foster a solution-oriented approach. Remember, the goal is to collect payment while preserving the opportunity for future business—not burn bridges.

5. Personalize the final communication

Understanding your audience is key to effective communication. When crafting your final communication, personalize the message based on your relationship with the client. This demonstrates your willingness to work with them while still emphasizing the need for payment.

For long-standing clients:

• Offer flexible payment options: This could include dividing the outstanding amount into smaller, more manageable installments via payment plans or extending deadlines. 

For new clients:

• Emphasize the consequences: Explain how late payments can negatively impact your cash flow, potentially hindering your ability to offer them the same level of service in the future. Provide context for why you may need to take serious action.

For clients with a history of late payments:

• Set firm expectations: Clearly state that continued late payments will lead to stricter terms, such as upfront deposits or paused services. If payment isn’t received by a specific date, inform them of potential late fees, collections involvement, or legal action.

Remind the client how your services or products benefit their business. This subtly reinforces the value they receive and incentivizes them to pay.

6. Take legal action

While legal action should always be a last resort, understanding when and how to involve collections agencies or legal counsel is crucial. Here's what you need to know:

• Consider the amount owed: For smaller amounts, the cost of legal action might outweigh the potential recovery.
• Gather documentation: Throughout the collection process, keep meticulous records of all communication attempts (emails, phone logs) and invoice copies. This strengthens your case if legal action becomes necessary.
• Consult a lawyer: Seek professional legal advice if the amount owed is significant or the client is unresponsive. They can guide you through the legal process and maximize your chances of recovering the full amount.

Remember, thorough documentation is key throughout the collection process. It serves as evidence of your efforts and strengthens your position if legal action becomes unavoidable.

7. Create a schedule to send the past-due invoice emails

If a client hasn’t paid on time, it’s important to follow up consistently without overwhelming them. A structured email schedule helps you escalate the situation gradually while giving the client multiple chances to pay. Here’s a simple schedule to follow:

• Day 1: A gentle reminder letting them know the invoice is now due. Sometimes, an email like this is all it takes.
• Day 7: A friendly follow-up in case they missed the first notice. Keep it polite but direct.
• Day 15: A firmer email emphasizing the overdue status and potential late fees.
• Day 30: A final warning before escalation, mentioning late fees, interest, or potential action.
• Day 60+: A serious notice stating that the invoice may be sent to collections or legal action may be taken.

Considerations to keep in mind when creating a past-due invoice email

No matter how overdue an invoice is, every follow-up email should be clear, professional, and to the point. Here are a few key things to include in every past-due invoice email:

Put the invoice number in the subject line

Your client probably has a full inbox, so make it easy for them to know exactly what your email is about. A subject line like “Friendly Reminder: Invoice #12345 Is Past Due” removes confusion and increases the chances they’ll open it.

Specify the due date and how late the invoice is

Always mention the original due date and how many days overdue the invoice has become. A quick reminder of when the payment was originally due helps reinforce the urgency. For example, "This is a friendly reminder that Invoice #12345, originally due on January 10, is now 15 days overdue."

Clearly state the amount owed

Don’t make your client search for details. Clearly list the outstanding balance in bold or in a separate line so it stands out. If late fees or interest have been applied, break down the new total.

Offer a direct link to pay

The easier it is for your client to pay, the better. If you accept online payments, include a direct payment link so they can take care of it in just a few clicks. If you accept multiple payment methods, list them out to remove any obstacles.

Give them a way to respond

Encourage them to reach out if they have questions or need to discuss a payment plan. A simple line like, “Let me know if there’s anything we can do to make this easier for you” keeps the conversation open.

Past-due invoice email templates and examples

If you’re not automating reminders, starting with a payment reminder template can help you write a professional and friendly past-due invoice letter. 

Customize these templates to your specific business and match the tone of your customer relationship to them. Below are guides to help you start.

Day 1: The payment due date

If you haven’t received the payment by the due date, check to see if your customer even received the bill. If you use QuickBooks, you can see whether a customer has viewed their invoice, which can tip you off that they might have overlooked the email.

Either way, send a polite email reminder mentioning that the invoice may have gotten lost in the shuffle. That might be enough to spur them into action. 

Invoice due email template:

Hi [Customer’s Name],

I hope this email finds you well.

This email is to notify you that payment on invoice #XXXXX for the amount of [invoice amount], which was sent on [sent date], is due today.

We have not yet received payment on this invoice and ask that you kindly confirm an ETA for the payment. If payment is not received by [late fee penalty date], a late fee will be charged.

We hope to avoid a late fee penalty, so if you have any questions about this invoice, please let us know; we will be happy to clarify.

Thank you,

[Your Name]

[Your Company Name]

Day 15: Two weeks late

If you haven’t received payment after your first reminder, it's a good time to reach out with a polite phone call. Reconfirm that your customer has the invoice, and see if they have any questions. 

You might also begin assessing late payment fees, but—this is important—only if you've already made the terms clear in your contract or onboarding process. Hitting a customer with an unexpected late fee could cause more animosity than it’s worth. However, it’s perfectly fine to state your terms for late payments upfront and then itemize them on the invoice.

15-day past-due invoice email template:

Hi [Customer’s Name],

I hope this email finds you well.

This email is to notify you that payment on invoice #XXXXX for the amount of [invoice amount] was due 15 days ago, on [due date].

We have not yet received payment on this invoice. [Optional, if applicable] As your invoice is now past its due date and grace period, a late fee of [amount] has been assessed.

The outstanding invoice amount is [invoice amount plus late fees, if applicable]. Attached is a copy of the invoice. You may make a payment here: [link to online payment or other payment methods].

Please update me with the status of your payment. Don't hesitate to reach out if you have any questions.

Thank you,

[Your Name]

[Your Company Name]

Provide clients with options for responding, like email and phone calls, to make it easier for them to address the issue.

Day 30: One month late

At this point, you might want to dial up your persistence. Be clear that you need to be paid, and make sure you’re talking to the right person. If you are dealing with an accounting department, it might be time to get your client involved again, as they have a vested interest in seeing you get paid in a timely fashion so the work can go on.

That’s because this is an ideal time frame to cease all current and future work. Politely let your client know via email that you will have to stop working on projects or products until the bills are current.

30-day past-due invoice email template:

Hi [Customer’s Name],

I am seeking your immediate attention to your invoice, which is now 30 days past-due.

Our records show that we have not yet received payment for invoice #XXXXX in the amount of [invoice amount], which was due on [due date].

[Optional, if applicable] As your invoice is past-due, a late fee of [amount] has been assessed.

The outstanding invoice amount is [invoice amount plus late fees, if applicable] and is [number of days] past-due. Attached is a copy of the invoice. You may make a payment here: [link to online payment or other payment methods].

Please let me know the status of your payment.

If your payment has already been sent, please disregard this notice. If you have any questions or concerns or would like to discuss payment plan options, please contact me at [contact number].

I appreciate you addressing this at your earliest convenience.

Thank you,

[Your Name]

[Your Company Name]

Day 60: Two months late

Depending on how large of a payment you're pursuing and how determined you are to collect the full amount, you may want to consider:

• Using an invoice factoring agency
• Sending the bill to a collections agency
• Writing the invoice off as bad debt and moving on

Using an agency comes with its own costs, but they might be more successful in collecting your past-due payment. Or it might be time to deem the payment a bad debt expense or an uncollectible payment that becomes a business expense if you don't get a payment from this final email.

Instead of just demanding payment, acknowledge there might be a reason for the delay and offer to work with them to find a solution, such as a payment plan.

Unpaid invoice email escalation

The traditional Net 15, 30, and 60-day overdue invoice reminders may not be conducive to your business plan. These alternative templates offer a flexible structure for crafting overdue invoice emails.

The reminder

For the first contact, send a polite reminder to the individual with a busy schedule. Dispatch this email one week before the payment is due to ensure they have sufficient time to make the payment.

Gentle reminder email template:

Hi [Client Name],

Just a friendly heads-up that your payment for account number [Account Number] is due next week on [New Due Date]. The outstanding balance is [Amount].

We understand that busy schedules can sometimes lead to overlooked deadlines. If you've already submitted payment, please disregard this email. Otherwise, we've made it easy for you to settle the invoice online through this link: [Link to secure payment portal] (if applicable).

The invoice is attached for your reference. Please don't hesitate to reach out if you have any questions about the invoice or need any assistance with the payment process.

Thanks,

[Your Name]

The nudge

This is the first request for action. You are now directly requesting payment. Send this email on the due date and keep it concise.

Nudging reminder email template:

Dear [Client Name],

This is a friendly reminder that your invoice # [Invoice Number] is due today, totaling [amount]. We've attached the invoice for your reference.

Your prompt payment is appreciated. For your convenience, we offer several easy payment options: [list payment options].

Please don't hesitate to contact us if you have any questions about the invoice or encounter any difficulties with the payment process. We're happy to assist you.

Thank you for your business.

Sincerely,

[Your Name]

Official notice

This is the first overdue invoice email, notifying the customer that their account is in default and immediate payment is required. Clearly outline any applicable late fees. Send this email one month after the payment due date.

Official notice email template:

Dear [Client Name],

This is a friendly reminder that your invoice # [Invoice Number] is past due. The total amount due is [amount]. We've attached the invoice for your reference.

We understand that things can sometimes slip through the cracks. If you've already submitted payment, please disregard this email.

To help us keep our records current, we encourage you to settle this invoice as soon as possible.

Should you have any questions or require assistance with the payment process, please don't hesitate to reach out. We're happy to help!

Thank you for your business.

Sincerely,

[Your Name]

Maintain a clear record of all communication regarding the invoice, including dates, emails, and phone calls.

The direct ask

At this stage, the tone needs to be more pressing. Inform the customer that late fees have been added and mention the possibility of their account being sent to collections to ensure they take notice. Dispatch this email two months after the payment due date.

Direct notice email template:

Dear [Client Name],

This email is to bring your immediate attention to invoice # [Invoice Number], which remains outstanding. The original due date was [original due date], making it significantly past due. The outstanding balance is [amount due], and a late fee of [late fee amount] has been applied, bringing the total due to [total amount due].

We understand unexpected situations can happen. However, to maintain a healthy business relationship, prompt payment is crucial.

Unfortunately, if this invoice remains unsettled within the next [number] business days, we will be forced to take further action. This may involve involving a collection agency, which could negatively affect your credit score and potentially incur additional fees.

To prevent these consequences, we strongly encourage you to prioritize settling this invoice immediately. The updated invoice with payment options is attached for your convenience: [list payment options].

If you've already submitted payment, please disregard this email and accept our apologies.

Sincerely,

[Your Name]

The final notice

At this stage, you may need to involve a collections agency to recover the amount owed. All late fees will be applied, the account will be closed, and the customer relationship will be terminated. Send this email three months after the payment due date.

Final notice email template:

Dear [Client Name],

This serves as your final notice regarding outstanding invoice # [Invoice Number] for [amount due]. This includes late fees totaling [late fee amount]. A final copy of the invoice is attached for your reference.

Unless payment is received in full within the next seven (7) business days, we will be forced to take further action. This may include:

• Closure of your account
• Referral to a collections agency, which could negatively impact your credit score and incur additional fees.

To avoid these consequences, we urge you to prioritize settling this invoice immediately. We offer several convenient payment options: [list payment options].

If you have already submitted payment, please disregard this email and accept our apologies for any inconvenience. Should you require assistance or have any questions about the invoice, please don't hesitate to contact us.

Sincerely,

[Your Name]

Tips for effective overdue invoice follow-up

Late client payments can wreak havoc on your small business’s cash flow. The past due invoice email templates can help you collect payments on invoices that are already overdue. There are steps you can take with other current customers and those you work with in the future to increase the likelihood of on-time payments.

1. Agree upfront to a preferred invoice payment process

For faster payments, hold the invoice conversation right at the start before you do the work. If it’s too late for that, don’t beat yourself up. There’s always next time.

It can be easier to get payment if you’ve determined these two specific logistics of what your client wants and needs in an invoice:

• Who should get the invoice: Sometimes it’s the client, sometimes it’s the accounting department, and sometimes it’s both. Make sure you know the procedure to expedite smoother, faster payment.

• How they like to pay: Offering your customers more payment options, such as credit card, eCheck, or direct ACH bank transfer, ensures that there’s no holdup for an easily avoidable reason.

It’s an extremely common situation: A client becomes accustomed to paying for almost everything one way, only to become inconvenienced when that payment method isn’t available. If they pay for everything by credit card, and you’re asking for a check, they may not ever find the time to locate their checkbook, get a stamp, and put the check in the mail.

2. Clarify what your customer is paying for and when it's due

Clients are more likely to pay on time when the invoice clarifies what they’re paying for. That’s why you want to make sure you’ve included all the information a client needs.

This could include:

• Consultation time
• Hours spent on specific tasks
• Research time
• Distinct project numbers for pre-defined deliverables
• Cost of materials

If you haven’t yet cataloged your products or services, it’s a worthwhile exercise that can make everything from marketing your business to sending invoices more efficient in the future.

Be proactive and remind customers of their outstanding payments. Sending a reminder that their payment is due next week gives them a heads-up. It might get the money you’re owed in your hands more quickly.

3. Establish a process for following up on past due invoices

Having “the conversation” about past-due payments is enough to have you chewing your nails and wiping your sweaty palms on your pants. When your nerves are already high, you don’t want to feel lost about what to do next. 

Having a system for following up on late payments can help you keep calm. The specifics of each system will differ from entrepreneur to entrepreneur, but a few things to consider include:

• Templates: Use pre-written email templates for payment reminders and overdue invoices to streamline communication.
• Late fees: Use pre-written email templates for payment reminders and overdue invoices to streamline communication.
• Reinforcements: For unresponsive clients, consider involving a lawyer or collections agency. Have this information readily available, just in case.

No two late payment situations are exactly the same, and you’ll need to respond accordingly. But having a system in place can help you determine your next steps with a little less panic and dread.

How to avoid or reduce past-due invoices

Chasing payments is frustrating, but you can take steps to reduce the number of past-due invoices before they even happen. Here are some ways you can make it easier for clients to pay on time and avoid the stress of constant follow-ups.

Set clear payment terms from the start

One of the biggest reasons invoices go unpaid is simple miscommunication. Before you start working with a client, make sure they know exactly when and how they need to pay. That means clearly outlining the following: 

• When payments are due (e.g., Net 15, Net 30, or payment upfront).
• Any late fees or interest charges for overdue invoices.
• The payment methods you accept (e.g., bank transfer, credit card, PayPal, etc.).

Make sure these terms are written in a contract or agreement so there’s no room for misunderstandings later.

Send invoices right away

The sooner you send an invoice, the sooner you get paid. Also, double-check that all the details (e.g., invoice number, due date, amount, and payment instructions) are correct to avoid confusion or unnecessary back-and-forth.

Offer multiple payment options

The more options you offer, the easier it is for clients to pay. Consider accepting credit/debit cards, ACH bank transfers, and online payment services. If possible, enable autopay for recurring clients so payments are automatically processed without them having to remember.

Automate your reminders

Automate your reminders so you don’t have to remember to send them manually. Most invoicing software platforms let you set up automatic payment reminders that go out at scheduled intervals— e.g., before the due date, on the due date, and after it passes.

Choose the best payment setup for your business

Choosing the best billing system for your business can significantly reduce the time and effort you spend chasing a past due invoice. By implementing clear terms for payments, offering convenient options, and establishing a professional communication strategy, you can ensure a smoother cash flow and maintain positive relationships with your clients.

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