How to Send Payment Reminders That Actually Work

The invoice is sent. The payment deadline has passed. And now what? You send a payment reminder. At least, that's what you should do. In practice, many business owners wait too long, send a message that's too cautious, or skip the reminder entirely because they're worried about damaging the client relationship.

The vast majority of SMBs deal with late payments. On average, a significant share of invoices aren't paid on time. Nearly a quarter of SMB owners lose more than EUR 20,000 a year to uncollectable invoices.

A good payment reminder is your first and best tool. This is everything you need to know about sending a payment reminder: when to send it, what to include, when to escalate to a formal demand, and why sending payment reminders by email alone isn't enough.

When to send your first invoice reminder

Timing makes the difference. Send too early and your reminder might cross with a payment already in transit. Send too late and you've given the customer weeks to forget about you.

The rule of thumb: send your first payment reminder 2 to 3 days after the payment deadline. Not sooner (the payment may still be processing), not weeks later.

Check your own records first. Has the payment perhaps already been received but not yet processed? Was the invoice sent to the right email address? A quick check prevents you from sending a friendly payment reminder for an invoice that's already been paid.

In most B2B contexts, a payment reminder isn't legally required before you can take further action. You could technically hand the invoice to a collection agency the day after the deadline. But in practice, a reminder is always the first step. It's professional, it works for genuine oversights, and it shows you take your accounts receivable seriously.

Note: consumer (B2C) collections have stricter rules in many jurisdictions. In the EU, for example, statutory grace periods and notice requirements apply before you can charge collection costs.

Make sure your payment terms are clearly stated in your terms and conditions and on the invoice itself. Under the EU Late Payment Directive, the default payment term for B2B transactions is 30 days. If you use different terms (14 days, 21 days), put them in writing. Without clear payment terms in your contracts, you have less ground to claim statutory interest or recovery costs later.

What a good payment reminder should include

There are no strict legal requirements for B2B payment reminders in most jurisdictions. But an effective reminder includes at minimum:

• The customer's name and address
• Invoice number and date
• The outstanding amount
• The original payment terms and due date
• A new payment deadline (5 to 10 days is standard)
• Your bank details for direct payment
• The original invoice as an attachment (so the customer doesn't have to search for it)
• A friendly but clear tone

Getting the tone right

The wording of your payment reminder matters more than you'd think. Too distant and it gets ignored. Too aggressive and you damage the relationship.

For the first reminder, assume good intent. Most outstanding invoices are the result of oversights, full inboxes, or delays in approval processes.

A good reminder example is short, factual, with a concrete request. Attach the original invoice so the customer can pay immediately without searching through their records. "Please remit payment of [amount] for invoice [number] within 7 business days." No apologies ("sorry to bother you"), no vagueness ("could you look into this when you get a chance").

For the second reminder, the tone can be more direct. Mention that you'll consider further steps if payment isn't received. Keep it brief: the longer the message, the less urgent it feels.

When to escalate: from reminder to formal demand

After two reminders without result, it's time for a formal payment demand. This isn't a third reminder with a different subject line. It's a step in the legal escalation process, and often the last step before you hand the claim to a third party.

The difference between a friendly reminder and a formal demand is the legal weight. A formal demand includes the consequences of non-payment:

• Statutory interest on the overdue amount (as established by the EU Late Payment Directive)
• A fixed minimum amount in recovery costs
• A specific deadline (typically 14 days)
• What happens next if payment doesn't arrive (collection agency, legal proceedings)

Include the available payment methods in your demand: a payment link, your bank details, or a summary of outstanding invoices. The easier it is to pay, the faster it happens.

Most European businesses don't exercise their right to charge interest and collection costs. Usually because they're afraid of damaging the client relationship. But including these costs in your demand isn't aggression. It's a business fact that raises the urgency.

Best practice: never send more than two formal demands. Most responses come after the first and the last. After an invoice, a couple of reminders, and two demands, the customer has had enough chances. Waiting longer lowers both your credibility and your collection odds. At that point, it's time to hand the claim to a collection agency or take the matter to court.

Why email alone doesn't work

Most businesses send their payment reminders by email. It makes sense: it's fast, cheap, and easy to automate. But the effectiveness is limited.

The average open rate for email reminders is low. That means more than half your customers never even see the reminder. Of those who do open it, many don't respond.

Phone contact has a much higher response rate. SMS reminders score even higher: a near-universal open rate, with 81% read within five minutes. Combining calls with SMS follow-up increases contact rates by 40% and improves promise-to-pay rates by 18%.

The problem with calling is capacity. Manual follow-up costs an average of EUR 0.90 per contact, compared to EUR 0.14 for an automated message. An AR clerk can make a limited number of calls per day. With a large receivables portfolio, the math doesn't work. So the smaller invoices get skipped, and those are exactly the ones that age into write-offs.

Automating payment reminders

The shift from manual to automated accounts receivable makes a measurable difference. Businesses that automate payment reminders see their collection rate rise from an average of 60% to 90-95%. Invoices get paid 30 to 50% faster.

But most automation tools stop at email. They send reminders on schedule, and that's it. For customers who genuinely forgot, that works fine. For the rest, it doesn't. And for business clients who are structurally late, you need more than an email reminder.

At Dunwise, we built accounts receivable software that handles the entire follow-up process. Our AI voice agent automates your receivables management from reminder to conversation. Not just the email reminder, but also the phone call that comes after. Every outstanding invoice gets a call on schedule. The tone adjusts automatically: friendly at 7 days, professional at 30, direct at 60.

Customer says "I never received the invoice"? The agent sends it via SMS during the call. Customer agrees to pay? The payment link arrives before the call ends. There's a dispute? The agent captures the details and routes them to your team.

The result: your payment reminders don't stop at email. Every invoice gets the follow-up it needs, without taking up your time.

Want to see how it works? Book a demo. The invoices you write off are almost always the ones nobody followed up on with more than an email. The sooner you send a payment reminder and follow up, the better your chances of getting paid.