How to Handle Unpaid Invoices: A 6-Step Escalation Plan

Unpaid invoices are common, and most are late rather than lost. Atradius reports that 7 in 10 businesses in the US, Canada and Mexico were paid late by B2B customers in its 2026 survey, and that most overdue receivables were settled within a month of the due date (Atradius, B2B payment practices trends in North America 2026). For small businesses the tail is longer: in Intuit QuickBooks' 2026 survey, 59% of US small businesses said they had invoices more than 30 days overdue (QuickBooks, Small Business Late Payments Report 2026). Our late payment statistics article explains why these surveys measure different things.

The practical point: the cause is usually an oversight, an approval queue or a client's cash flow, not a refusal. A calm, documented process gets most of these paid and leaves you with a clean paper trail for the few that do not.

The escalation timeline

How do you collect on unpaid invoices? Follow a structured escalation: a friendly reminder within a few days of the due date, a firm follow-up and phone call at 7-14 days, a formal demand at about 30 days, a final notice with a deadline, a pause on new work, and third-party recovery after that. The day counts below are a common pattern, not a legal requirement.

Step 1: Friendly reminder (1-3 days overdue)

Most late payments are unintentional. The client forgot, the invoice landed in the wrong inbox, or accounts payable has not reached it yet. Start by assuming that.

What to do:

• Send a short email that names the invoice number, amount and due date
• Reattach the invoice
• Include a payment link or your bank details
• Keep the tone light

Example email:

"Hi [Name], just a quick note that invoice #[NUMBER] for $[AMOUNT] was due on [DATE]. I've reattached it for your convenience. You can pay online here: [link]. Let me know if you have any questions. Thanks!"

Put each follow-up date on your calendar so the next step does not depend on memory. The free payment reminder tool gives you three fixed templates (gentle, firm and final) with placeholders to fill in and copy into your own email. If you use InvoiceQuickly Pro, you can turn on scheduled reminders before and after the due date instead; see automatic payment reminders for how they work and what they do not do.

Step 2: Direct follow-up (7-14 days overdue)

If the friendly reminder got no reply, be more direct. The goal is a response, not pressure.

What to do:

• Send a follow-up email with a firmer tone
• Call the client (an email is easy to ignore; a call is not)
• Ask whether anything is wrong with the invoice or the work
• Ask for a specific commitment: "Can you confirm payment by [date]?"

On the phone call: Be direct but professional: "I'm calling about invoice #[NUMBER] for $[AMOUNT] that was due on [DATE]. I wanted to check if there's anything preventing payment." This often uncovers the real issue: the invoice went to the wrong email, a purchase order number is missing, or the approver is away. If the client disputes part of the invoice, switch to the process in how to handle disputed invoices and keep chasing the undisputed part.

Step 3: Formal payment demand (15-30 days overdue)

Now move from reminders to documentation. You are building a record you can rely on if the debt escalates.

What to do:

• Send a formal demand letter by email and by post
• Reference the contract, purchase order or written agreement
• State the total due, including any late fee or interest your contract or the law allows
• Set a clear deadline, such as 7-10 days from the letter date
• Say what you will do next if payment does not arrive

Late fees and interest: you can usually add only what the client agreed to in advance or what a statute gives you.

• United States: there is no single national rule. Each state sets its own interest and usury limits. For example, Texas allows 6% a year legal interest from the 30th day after an amount is due when no rate was agreed (Texas Finance Code §302.002), and California applies 10% a year after a breach when the contract set no rate (California Civil Code §3289). See late fee laws by state before you set a rate.
• United Kingdom: for business-to-business debts, the Late Payment of Commercial Debts (Interest) Act 1998 lets you claim statutory interest of 8% plus the Bank of England base rate, unless your contract sets a different rate. For debts that become overdue between July and December 2026 that is 11.75% (8% plus the 3.75% base rate on 30 June). You can also claim a fixed sum for recovery costs: £40 for debts under £1,000, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more (GOV.UK).

Worked example (UK, B2B): a £5,000 invoice paid 30 days late in October 2026. Annual interest is £5,000 × 11.75% = £587.50, so daily interest is £587.50 ÷ 365 = £1.61. Thirty days comes to £587.50 × 30 ÷ 365 = £48.29. Add the £70 fixed recovery sum and the demand is £5,000 + £48.29 + £70 = £5,118.29. The late fee calculator runs the same simple-interest arithmetic for any rate and number of days.

Step 4: Final notice (30-45 days overdue)

What to do:

• Send a notice clearly labelled "Final notice"
• State the total owed, including any lawful late fee or interest
• Give a firm deadline, such as 5-7 days
• Name the specific next step: pausing work, referring the debt to a collection agency, or starting a small-claims or court claim
• Send it by a tracked method (certified mail in the US, Royal Mail Signed For or Special Delivery in the UK) so you can prove receipt

Keep records of everything. Save every email, note every call (date, time, who you spoke to, what was said) and keep copies of every letter. A past-due invoice template helps you restate the original amount, the days overdue and any agreed charges in one document.

Step 5: Pause work (45-60 days overdue)

If you are still delivering work for this client, stop. Continuing to work while invoices go unpaid means you are financing their business.

What to communicate: "Due to the outstanding balance of $[AMOUNT] on invoice(s) #[NUMBERS], I'm pausing all current work effective [date]. Work will resume within [X days] of full payment of the outstanding balance."

Check your contract first. Many service agreements include a clause allowing suspension for non-payment. If yours does not, add one to future contracts; our client contract templates guide covers payment and suspension clauses.

Step 6: Third-party recovery (60-90 days overdue)

When direct efforts fail, bring in outside help.

Option A: Collection agency

Commercial collection agencies usually work on contingency, keeping a percentage of what they recover. Rates vary with the age and size of the debt, so get the fee, any minimums and the reporting process in writing before you sign. An agency makes most sense when the client can pay but has stopped responding.

Option B: Small claims court

Small claims courts handle lower-value debts without requiring a lawyer. The maximum claim, filing fees and procedure differ by state in the US and by nation within the UK, so check your court's official small-claims page before you file.

Option C: Mediation

A neutral mediator helps both sides reach an agreement. It is usually faster and less adversarial than court, and some business contracts require it before litigation.

Option D: Attorney

For larger amounts, a letter from an attorney or solicitor often prompts payment, because defending a claim costs the client more than paying the invoice. Some lawyers take collection cases on contingency.

This is general information, not legal advice. Check your contract and your local rules, or speak to a lawyer, before charging interest or starting a claim. Last reviewed: October 28, 2026.

Prevention: how to avoid unpaid invoices

The best collection process is one you rarely need. These habits reduce the risk of non-payment.

1. Ask new clients for a deposit

For new clients or large projects, ask for part of the fee upfront. A client who will not pay anything before work starts is a warning sign. A deposit invoice template shows one way to bill it.

2. Check client references

For large projects, ask other suppliers or freelancers who have worked with the client whether they pay on time. One short conversation can save months of chasing.

3. Use clear contracts

Every engagement needs a written agreement covering scope, payment terms, late fee policy and dispute resolution. Keep it simple but explicit, and agree any late fee before the work starts.

4. Invoice promptly

The later you invoice, the later you are paid. Invoice on delivery. Our guide on when to send an invoice covers timing.

5. Make payment easy

Offer the payment methods your clients actually use, such as bank transfer, card or PayPal, and put a payment link or bank details on every invoice. See invoice payment methods for the trade-offs.

6. Put reminders on a schedule

Manual follow-up slips when you are busy. Either put reminder dates on your calendar and use the payment reminder tool templates, or use scheduled reminders in InvoiceQuickly Pro.

7. Shorten payment terms

Net 30 is common but not mandatory. For small projects and new clients, Net 15 or due on receipt shortens the time you are exposed.

8. Weigh early-payment discounts carefully

A 2% discount for payment within 10 days (2/10 net 30) can speed up payment, but it is expensive: giving up 2% to be paid 20 days earlier works out to about 36.5% a year on a simple basis. Run your own numbers in the discount calculator first.

What not to do

• Don't get emotional. Stay professional in every message. Angry emails damage the relationship and read badly if the dispute escalates.
• Don't threaten without following through. If you say you will refer the debt by a date, do it. Empty threats teach clients to ignore you.
• Don't harass. Several calls or emails a day crosses from persistence into harassment. Follow your timeline.
• Don't write off too soon. One or two unanswered reminders is not the end of the process.
• Don't keep working. Delivering more work for a client who is not paying rewards the behaviour.

Tracking overdue invoices

Keep a simple log of every outstanding invoice:

In InvoiceQuickly, each invoice shows its status (draft, sent, viewed, overdue, paid or cancelled) and the remaining balance after any payments you record. You can record full or partial payments on every plan; there is no separate "partially paid" status, so a part-paid invoice keeps its status with a lower balance until it is paid in full. The "overdue" status is set when a Pro scheduled overdue reminder is sent, so on the Free plan, check due dates yourself.

The bottom line

Most unpaid invoices get paid with a steady, documented escalation. Start friendly, get firmer on a timeline, charge only the late fees or interest you are entitled to, and bring in third parties when direct contact fails. Invoice promptly, keep records of everything, and stop working for a client who is not paying.

Track and manage all your invoices with InvoiceQuickly →