Chasing an unpaid invoice from reminder to formal demand

Key rules

• Formal demand: A formal demand by burofax gives the client 8 to 10 days to pay.
• Time limit: You have 5 years from the due date to claim, and a formal written demand restarts the clock.
• Proof: Use a delivery method that proves content and date; a plain email is easier to challenge.
• Stopping work: Check your contract and send written notice before you suspend work, or you risk a damages claim.

Start gently, and keep everything in writing

Most late invoices get paid after a polite reminder. Escalate one step at a time, and keep a written record of each step. If you end up in court, that record is your evidence. The timings below are practical habits, not legal requirements.

Step 1: a friendly email

Send a short email within a few days of the due date. Assume it was an oversight. Attach the invoice again and ask for a payment date.

Step 2: a firmer reminder

If nothing happens after about 7 to 15 days, write again. Attach a copy of the invoice, say it is overdue, and mention that late-payment interest and a fixed recovery fee of 40 euros can be charged on business debts. The template below has wording you can adapt.

Step 3: call, then confirm in writing

Phone the client and ask what is holding up payment. Straight afterwards, email a summary of what was said and any date they promised. A call alone proves nothing.

Step 4: the formal demand

This is the final notice. Send it in a way that proves what you sent and when it arrived. The demand gives the client 8 to 10 days to pay. State the amount, the invoice numbers, the interest and the 40 euro fee, and say you will go to court if they do not pay.

Your options, from strongest to weakest:

• Burofax with certified text and acknowledgement of receipt. Correos issues it. It proves the exact content, the delivery date and who received it. Courts accept it as evidence. It costs a mid-range price.
• Notarial demand (requerimiento notarial). A notary delivers and records the demand. It has very strong evidential value, but costs more, typically tens to a few hundred euros.
• Certified email service. It records the sending and the content. It is a cheaper option.
• Plain email. It is cheap, but easier for the client to challenge. It helps most if the client replies or opens it.

A registered letter without certified content proves less, so avoid it. If a burofax is not delivered, the sending still has some value as evidence, but you will have to show the client received or avoided it. In that case, try a second delivery route, such as a notarial demand or certified email.

Any written reply, or an admission that the debt is owed, is useful evidence. Keep it.

Stopping work

Be careful. Spanish law lets you pause work when the client seriously breaches the contract, but a minor delay is not enough. Your response must be proportionate and in good faith. Wrongly stopping can expose you to a damages claim or to the client ending the contract for your breach. Read your contract for notice and suspension clauses first, and send written notice that you intend to suspend before you do. Public-sector contracts have their own formal notice rules.

Mind the time limit

You have 5 years from the due date to claim an unpaid invoice. A formal written demand such as a burofax restarts the clock. So does the client acknowledging the debt, and so does a court claim. Debts that arose before 7 October 2015 follow transition rules. Catalonia and other regions with their own civil law may have different periods, so check if that applies to you.

If the deadline passes unpaid

Do not keep writing. Hand your file to a lawyer, who can file a court claim for payment. Give them your contract, invoices, and the full message trail. The court stage is covered by legal help, not by this page.

The timeline, documents and checklist below walk you through the same steps. If the client disputes the work or goes silent, see the section on that case.

Timeline and deadlines

• Send a firmer reminder with a copy of the invoice and a note on interest: About 7 to 15 days after the due date

• Phone the client and confirm the call in writing: After the firmer reminder goes unanswered

• Send a formal demand by burofax or certified email: After the call, giving the client 8 to 10 days to pay

• Hand the file to a lawyer to file a court claim: If the 8 to 10 days pass without payment

• Make sure your claim is made before the time limit ends: Within 5 years of the due date, restarted by a formal written demand

Documents you need

• Burofax with certified text and acknowledgement of receipt, issued by Correos. It proves the sending, the exact content, the delivery date and the recipient, and a court accepts it as evidence. Keep the receipt and the delivery confirmation.

• Notarial demand (requerimiento notarial), issued by a notary who delivers and records the demand. Use it instead of a burofax if you want the strongest evidence and accept the higher cost.

• Your signed contract with the client, to check for notice and suspension clauses before you stop work.

• A written notice that you intend to suspend work, sent to the client before you stop. It is advisable, not always required.

Checklist

• Send a firmer reminder with a copy of the invoice and a note on interest after 7 to 15 days.

• Phone the client and confirm the call in writing straight afterwards.

• Send a formal demand by burofax or certified email that gives 8 to 10 days to pay.

• Read your contract for notice and suspension clauses before you stop work.

• Send written notice that you intend to suspend work before you stop.

• Keep every message, reply and delivery receipt together in one folder.

• Hand the file to a lawyer to file a court claim if the deadline passes unpaid.

What if the client disputes the work or goes silent?

Your evidence of the agreement and of delivery decides which options you have and how strong they are. Gather it before you do anything else.

Gather your evidence first

Collect these before you contact the client again:

• The contract, quote or brief that sets out what was agreed.
• Emails and messages where the client accepts the scope, approves drafts or comments on the work.
• Proof of delivery: sent files, delivery emails, timesheets, shared-folder logs.
• The invoice and proof that it was sent.

Without this, a client who says "I never agreed to that" is hard to answer. With it, even a stubborn client usually has little room to argue.

If the client disputes the work

1. Negotiate in writing. Ask the client to say exactly what they dispute. Offer a fix or a partial discount if that is cheaper than a fight. Keep everything in email so it counts as evidence.
2. Try mediation. It is voluntary, so the client must agree to it. It is often faster and cheaper than court.
3. Send a formal demand. A burofax from Correos with certified text and acknowledgement of receipt proves what you sent, when, and who received it. Courts accept it as documentary evidence. It also fixes the date of your demand and can interrupt the time limit for claiming.
4. Go to court. The order-for-payment procedure (proceso monitorio) is meant for debts the client does not dispute. If the client opposes it, the case moves to an ordinary trial. For claims up to 15,000 euros that is a verbal procedure. Check the current thresholds and any pre-court negotiation step with the court or a lawyer, as these rules have recently changed.

Check your contract for an arbitration clause. If there is one, the dispute may have to go there instead of court.

If the client goes silent

Silence is not a dispute, so the order-for-payment route is open to you if the debt is for a fixed sum and you can document it.

1. Send a burofax or an email with proof of delivery. Say the invoice is overdue and give the 8 to 10 days to pay. Payment is due within 30 days of delivery unless you agreed a longer term, which can be 60 days at most.
2. File the order-for-payment claim with the court of first instance where the client lives. For claims up to 2,000 euros you need no lawyer or procurador. The client then has 20 working days to pay or oppose.
3. Enforce. If the client does not respond, the court issues an enforcement order and you can pursue their assets.

If the client is a business abroad in the EU, a European order-for-payment procedure may apply instead.

If the client is insolvent or has closed

Look the company up in the Registro Mercantil and the Registro Público Concursal before spending money.

• Insolvency (concurso de acreedores): report your debt to the insolvency administrator within one month of the declaration being published in the Registro Público Concursal. Late claims are generally paid last.
• Dissolved company: you may be able to pursue the former liquidators or partners, up to the share of the company's assets they received. You can also ask for the liquidation to be reopened. Take legal advice before starting this.

Watch the clock and the cost

Claims for unpaid work generally expire after 5 years, but do not wait. Evidence goes stale and clients disappear. For small amounts, compare the cost and time of action with what you would recover. A burofax and a firm deadline often settle it without court.

Payment reminder and formal demand wording

Copy the version that fits where you are in the chase. Replace each blank in square brackets. Send every message in writing and keep a copy.

1. Friendly reminder (a few days after the due date)

Asunto: Recordatorio de pago, factura [número]

Hola [nombre]:

Te escribo para recordarte que la factura [número], de fecha [fecha], por importe de [importe] euros, venció el [fecha de vencimiento] y todavía no consta el pago. Te la adjunto de nuevo.

Si ya lo has pagado, te agradecería que me enviaras el justificante. Si no, ¿puedes confirmarme cuándo se hará la transferencia?

Un saludo, [tu nombre]

2. Final notice (about 7 to 15 days after the first reminder)

Asunto: Segundo aviso, factura [número] pendiente de pago

Hola [nombre]:

Te escribí el [fecha del primer recordatorio] sobre la factura [número], por [importe] euros, vencida el [fecha de vencimiento]. Sigue sin pagarse. Te adjunto una copia.

Te recuerdo que, en las operaciones comerciales entre empresas y profesionales, el retraso en el pago genera intereses de demora automáticamente desde el día siguiente al vencimiento, sin necesidad de aviso previo. Además, se puede reclamar una cantidad fija de 40 euros por costes de cobro.

Te pido que realices el pago antes del [fecha] en la cuenta [IBAN]. Si no, tendré que reclamarlo formalmente.

3. Formal demand (by burofax, or email with certified delivery)

Asunto: Requerimiento formal de pago, factura [número]

[Nombre o razón social del cliente] [NIF] [Dirección]

[Ciudad], a [fecha]

Yo, [tu nombre completo], con NIF [tu NIF] y domicilio en [tu dirección], le requiero formalmente el pago de lo siguiente:

• Factura [número], de fecha [fecha], por servicios de [descripción], por importe de [importe] euros, con vencimiento el [fecha de vencimiento].

Hechos:

1. El servicio se prestó el [fecha] y la factura se le entregó el [fecha de entrega], sin que haya sido impugnada.
2. A fecha de hoy la factura permanece impagada, pese a los recordatorios enviados el [fecha] y el [fecha].

De acuerdo con la normativa sobre morosidad en las operaciones comerciales, la deuda devenga intereses de demora desde el día siguiente al vencimiento, al tipo del Banco Central Europeo más 8 puntos porcentuales, revisado cada semestre. Los intereses calculados hasta hoy son [importe] euros. Seguirán devengándose hasta el pago completo.

Esa misma normativa me da derecho a una cantidad fija de 40 euros por costes de recuperación, sin necesidad de acreditarlos, además de cualquier otro coste de cobro que pueda justificar.

Por tanto, le reclamo:

• Principal: [importe] euros
• Intereses de demora hasta hoy: [importe] euros
• Total a hoy: [importe total] euros

Dispone de [8 a 10 días] naturales desde la recepción de este requerimiento para ingresar esa cantidad en la cuenta [IBAN]. Transcurrido ese plazo sin pago, iniciaré las acciones judiciales que correspondan, incluido el procedimiento monitorio, y reclamaré también las costas y los gastos que se generen.

Atentamente, [tu nombre y firma]

How to use these

• In the formal demand, keep a number of days between 8 and 10, so the deadline matches what a burofax normally allows.
• To work out the interest, take the European Central Bank rate in force on the first day of the half-year, add 8 percentage points, and apply it to the unpaid amount for each day of delay. The rate is published every half-year, so check the current one in the official gazette before you fill in the figure.
• If you and the client agreed a different late-payment rate in writing, use that one instead, as long as it is not grossly unfair to you.
• These wording options are for invoices between businesses or freelancers. They do not apply to a private consumer.

Frequently asked questions

Can I stop work while an invoice is overdue?

Yes, you can pause work, but only if the non-payment is serious enough to defeat the purpose of the contract, and a minor delay does not qualify. Pausing must be proportionate and in good faith, and a wrongful pause can expose you to a damages claim or to the client ending the contract for breach.

Is a plain email enough as a formal demand instead of a burofax?

A plain email can work as a demand, but it is easier to challenge unless the client replies or opens it. Certified email services record the sending and content, and a notarial demand (requerimiento notarial) has strong evidence value. A notary costs more, typically tens to a few hundred euros. A burofax sits in the middle on price. A written reply from the client is also useful evidence.

What happens if the burofax is not delivered?

An undelivered burofax still has some evidence value, because the sending itself is recorded. You will still have to show that the client received it. Keep the Correos receipt and consider a second method, such as a notarial demand.

Does the time limit for claiming an invoice differ in Catalonia?

Yes, Catalonia and other regions with their own civil codes have their own limitation periods, so the general period may not apply to you. Debts that arose before 7 October 2015 also follow transition rules. Ask a lawyer which period covers your invoice before you rely on any date.