Email gets ignored. A formal letter, physical or PDF, gets attention. Here's exactly what to send when an invoice is 30, 60, or 90 days overdue, plus the legal escalation timeline behind it.
When to switch from email to letter
After 14 days of email silence, your messages have stopped registering as anything urgent. They sit in the same inbox as the newsletters your client never reads. If you've already sent two or three follow-ups with no response, sending a fourth email is just adding to the noise. The format is the problem, not the content.
A letter, whether it's a PDF attached to a short email or a physical copy mailed to their business address, signals that the situation has changed. It looks different, it reads different, and it lands different. Most clients haven't received a formal collection letter in years, if ever. The novelty alone makes them pay attention.
Letters also have legal weight in a way that email threads don't. If this ends up in small claims court or with a collections agency, a paper trail of formal letters with delivery confirmation is exactly the documentation you need. "I emailed them six times" is weaker evidence than "here are three certified letters with signed return receipts."
Finally, the format itself communicates a message your email body can't: we're done with email. The relationship has shifted from casual back-and-forth to formal demand. That shift, on its own, is sometimes enough to trigger payment.
Letter format basics
Every overdue invoice letter, regardless of how late the invoice is, should include these elements:
- Your letterhead at the top — business name, address, phone, email
- The date you're sending the letter
- The recipient's name, title, and full business address
- Invoice details — invoice number, original date, due date, amount, and days overdue
- A numbered list of every prior reminder you've sent, with date, channel, and a one-line description
- A clear demand and a specific deadline (not "soon" — give a date)
- The consequence if the deadline passes (late fees, collections, small claims filing)
- Your signature, printed name, and title
Skipping any of these weakens the letter. The numbered prior-reminder list is especially important because it shows a court or collections agency that you gave the client every reasonable chance to respond.
Template 1: 30-day overdue letter (the polite formal)
This is your first formal letter. Tone: professional, firm, but still gives the client the benefit of the doubt. Maybe the invoice slipped through. Maybe they're traveling. The 30-day letter says "we noticed, and we need this resolved" without burning the relationship.
{Your Business Name}
{Your Address}
{City, State ZIP}
{Phone} | {Email}
{Date}
{Client Name}
{Client Title}
{Client Business Name}
{Client Address}
{City, State ZIP}
RE: Overdue Invoice {Invoice #} — {Amount}
Dear {Client Name},
This letter is a formal notice that Invoice {Invoice #}, dated {Original Date}
in the amount of ${Amount}, is now 30 days past its due date of {Due Date}.
For your records, we have previously contacted you regarding this invoice:
1. {Date} — Initial reminder email
2. {Date} — Follow-up email
3. {Date} — Phone call / second follow-up
We understand things come up. If there is an issue with the invoice or a
question about the work delivered, please reach out so we can resolve it.
If you have already sent payment, please disregard this letter and let me
know so we can confirm receipt on our end.
Otherwise, we ask that you remit the full balance of ${Amount} by
{Deadline — 14 days from letter date}. Per the terms of our original
agreement, a late fee of {1.5%}/month applies to balances 30+ days overdue,
and ${Late Fee Amount} has been added to your account.
You can pay online at {payment link} or by check made payable to
{Your Business Name} at the address above.
Thank you for your prompt attention to this matter.
Sincerely,
{Your Signature}
{Your Printed Name}
{Your Title}
Most freelancers never need to send a 60-day letter because PaymentPing's reminders catch the issue at days 1, 7, and 14, when it's still fixable. See how it works.
Template 2: 60-day overdue letter (the firm)
The polite tone is gone. The 60-day letter references the prior letter, applies late fees, and warns of collections submission. You're still being professional, but you're done being patient.
{Your Business Name}
{Your Address}
{City, State ZIP}
{Phone} | {Email}
{Date}
{Client Name}
{Client Title}
{Client Business Name}
{Client Address}
{City, State ZIP}
SECOND NOTICE — OVERDUE INVOICE {Invoice #}
Dear {Client Name},
On {Date of First Letter}, we sent a formal letter regarding Invoice
{Invoice #}, originally dated {Original Date} for ${Original Amount}.
That letter has gone unanswered. The invoice is now 60 days overdue.
Prior contact regarding this invoice:
1. {Date} — Initial reminder email
2. {Date} — Follow-up email
3. {Date} — Phone call / second follow-up
4. {Date} — First formal letter (sent via {certified mail / email})
The current balance, including late fees applied per our agreement, is now:
Original invoice: ${Original Amount}
Late fees (60 days): ${Late Fee Total}
----------------------------------------
TOTAL DUE: ${Current Balance}
We require payment in full by {Deadline — 14 days from letter date}.
If we do not receive payment or a written response by that date, this account
will be submitted to a third-party collections agency on {Specific Date}.
Collections proceedings will be reported to credit bureaus and may impact
your business's credit standing.
To avoid this outcome, please pay online at {payment link}, mail a check to
the address above, or contact us directly to arrange a payment plan. We are
willing to discuss reasonable arrangements if there is a genuine hardship.
This is your opportunity to resolve this matter before formal action begins.
Sincerely,
{Your Signature}
{Your Printed Name}
{Your Title}
Template 3: 90-day overdue letter (the final)
This is your last letter before formal action. It references both prior letters, states the specific next step, and gives a tight deadline. Some businesses send this from an attorney's letterhead instead — that costs $100 to $300 and dramatically increases response rates.
{Your Business Name}
{Your Address}
{City, State ZIP}
{Phone} | {Email}
{Date}
{Client Name}
{Client Title}
{Client Business Name}
{Client Address}
{City, State ZIP}
FINAL NOTICE BEFORE LEGAL ACTION — INVOICE {Invoice #}
Dear {Client Name},
This is the final notice you will receive from us regarding Invoice
{Invoice #}, originally issued on {Original Date} in the amount of
${Original Amount}. The invoice is now 90+ days overdue.
We have previously contacted you on the following dates:
1. {Date} — Initial reminder email
2. {Date} — Follow-up email
3. {Date} — Phone call
4. {Date} — First formal letter (30-day notice)
5. {Date} — Second formal letter (60-day notice, certified mail)
Each prior communication has gone unanswered. The current balance, including
all late fees through {Today's Date}, is:
Original invoice: ${Original Amount}
Late fees (90 days): ${Late Fee Total}
----------------------------------------
TOTAL DUE: ${Current Balance}
You have 7 days from the date of this letter to do one of the following:
1. Pay the full balance of ${Current Balance} via {payment link} or check
2. Contact us in writing to arrange a binding payment plan
3. Provide a documented dispute regarding the goods or services delivered
If we do not hear from you by {Specific Deadline Date}, we will pursue one
or more of the following remedies without further notice:
- Submission to a third-party collections agency, with credit bureau
reporting that will affect your business's credit
- Filing a small claims court action in {Your County, State}, where you
will be required to appear and may be liable for court costs and fees
- Referral to our attorney for further legal action
We would prefer to resolve this without legal proceedings. The fastest way
to do that is to pay the balance or contact us today.
This letter constitutes formal notice of intent to pursue legal remedies.
Sincerely,
{Your Signature}
{Your Printed Name}
{Your Title}
CC: {Attorney Name, if applicable}
How to deliver the letter
How you send the letter matters almost as much as what's in it. For all three letters above:
- Send the PDF by email AND mail a physical copy via certified mail with return receipt requested
- Why both: certified mail with a signed return receipt is legal proof of delivery, which email can't provide. The client can claim they "missed the email." They can't claim they didn't sign for the certified letter.
- For high-value invoices over $5,000, consider sending the 90-day letter via an attorney. Most lawyers will write and send a demand letter on their letterhead for a flat fee of $100 to $300, and the response rate is dramatically higher than a letter from you. You don't need a retainer for this.
A certified letter costs around $5. The signed return receipt is your single most valuable piece of evidence if this ends up in court.
What "late fees" should you charge?
Late fees vary by jurisdiction, but the most common range is 1% to 1.5% per month on overdue balances after the original net term ends. Most US states allow this. A few have caps. Check your state.
Important: you can only charge a late fee if you disclosed it in advance. That means it has to be on the original invoice or in the contract the client signed. You cannot retroactively add late fees to an invoice that didn't mention them. If your invoices don't include late fee language, add it now for future work, but don't try to apply fees to old invoices.
If you didn't disclose late fees and the client asks, you can still charge "interest on overdue balances" in many jurisdictions, usually capped at the state statutory rate (often around 5% per year). It's worth a polite ask, but don't fight over it. The principal balance is what matters.
For more on how to set up late fees correctly so they actually work, see our late payment fees guide.
When to escalate to collections vs small claims
Once the 90-day letter expires with no payment, you have three options. Pick based on the size of the debt and how much energy you want to spend.
Small claims court is the DIY route. Limits vary by state, typically $5,000 to $25,000. Filing fees run around $50. You don't need a lawyer. You file, the court summons the client, and you make your case in front of a judge. If you have a signed contract, an itemized invoice, and your stack of certified letters with return receipts, you'll usually win. Collecting on the judgment is a separate problem, but the judgment itself becomes a public record that affects the client's credit.
Collections agencies handle any amount, but they take a cut, usually 25% to 50% of what they recover. You sign over the debt, they pursue it through phone, mail, and credit bureau reporting. You get whatever's left. Collections is the right call when you don't want to deal with court and the debt is large enough that even half is worth more than zero.
An attorney letter is the middle ground. For $100 to $300, an attorney writes and sends a formal demand on their letterhead. Roughly half the time, this alone produces payment because the client realizes you're serious. If it doesn't work, you've still spent a fraction of what collections would cost, and you can escalate from there.
For most freelancers with invoices under $10,000, the order of escalation is: attorney letter, then small claims, with collections as a last resort if you can't be bothered with court. For more on the back-and-forth before you get this far, see our guide on how to chase late payments.
Closing
If you're sending a 90-day letter, you've already lost the relationship. The client isn't coming back, and you wouldn't want them if they did. The point of the letter isn't to save the relationship. It's to recover what you're owed and document the trail in case you need to escalate.
The better play is never getting to 90 days in the first place. Most overdue invoices stay overdue because nobody followed up consistently after day one. Automated reminders at days 1, 7, and 14 catch the vast majority of late payments before they need a formal letter. PaymentPing handles this for you so the only letters you ever write are the rare ones for clients who were never going to pay anyway.