Unpaid Business Invoice in Portugal: Interest, Injunção and Debt Collection

An unpaid business invoice in Portugal should not be treated as only an accounting problem.

Once payment is overdue, the next legal step depends on:

• who the debtor is;
• what contract produced the invoice;
• whether the debt is disputed;
• whether the transaction is a qualifying commercial transaction;
• whether you already have an executive title;
• whether the debtor has assets.

For a straightforward B2B supply or services debt, the Portuguese injunção procedure can be an efficient route.

But an invoice alone does not automatically allow you to seize the debtor's assets.

Start with the contract, not only the invoice

Collect:

• signed contract or order;
• accepted proposal;
• purchase order;
• delivery evidence;
• service records;
• invoice;
• payment terms;
• emails and messages;
• debtor acknowledgment;
• partial-payment history;
• any complaint about the goods or services.

The invoice proves what was billed.

The underlying file proves why the money is due.

This becomes critical if the debtor opposes the debt.

When is the invoice overdue?

If the contract sets a fixed due date, the payment becomes late when that date passes.

In qualifying commercial transactions between businesses, Portuguese late-payment law generally makes statutory commercial interest run from the day after the agreed due date without requiring a separate payment demand.

Where the contract does not specify the due date, Decreto-Lei n.º 62/2013 contains automatic timing rules, including 30-day periods linked to receipt of the invoice, goods or services.

Do not apply consumer-debt rules to a B2B transaction without checking the legal category.

Commercial late-payment interest

For qualifying commercial transactions, late-payment interest can be due at:

• the valid contractual rate; or
• the applicable statutory commercial rate.

The statutory commercial rate is published periodically.

Do not hard-code an old percentage into a demand letter.

Calculate the rate applicable to each period of delay.

The EUR 40 recovery-cost amount

Decreto-Lei n.º 62/2013 gives a creditor in a qualifying commercial transaction a minimum EUR 40 amount for recovery costs where late-payment interest is due.

This amount is available without a separate demand.

If reasonable recovery costs are higher, the creditor can potentially claim more with evidence.

This rule is not a universal EUR 40 surcharge for every Portuguese debt.

It belongs to the statutory commercial-transaction framework.

Send a structured formal demand

A good pre-action demand should identify:

• creditor;
• debtor;
• contract;
• invoice numbers;
• principal outstanding;
• due date;
• interest basis;
• recovery costs where applicable;
• final payment date;
• payment details;
• next legal step if payment is not made.

The purpose is not to write an aggressive letter.

The purpose is to remove ambiguity.

A strong demand also becomes useful evidence of the collection history.

Should you use injunção?

Often, for a clear monetary debt arising from a contract.

In general, the Portuguese injunção regime is available for monetary contractual claims up to EUR 15,000.

For qualifying commercial transactions covered by Decreto-Lei n.º 62/2013, injunção can be used irrespective of the amount of the debt.

That distinction is important.

A B2B invoice of more than EUR 15,000 is not automatically outside injunção if it falls within the commercial-transaction regime.

What happens after the injunção is filed?

The debtor is notified.

The debtor can:

• pay;
• do nothing;
• oppose the claim.

If the debtor is properly notified and does not oppose, the injunção can receive the enforceability formula.

It then becomes an executive title capable of supporting enforcement.

That is the main practical value of the procedure.

What if the debtor opposes?

Then the dispute becomes judicial.

The court needs to decide the claim.

For commercial transactions, the procedural route after opposition depends in part on the claim value.

Claims above EUR 15,000 move into ordinary proceedings under the current Article 10 framework.

At or below that value, the statutory special declaratory route can apply.

Do not describe injunção as an automatic debt judgment if the debtor contests the claim.

What if the debtor says the service was defective?

Then the matter is no longer only an unpaid-invoice problem.

The dispute can involve:

• defective performance;
• price reduction;
• set-off;
• damages;
• contract termination;
• counterclaim.

Review the commercial contract breach position before deciding the claim structure.

A weakly prepared injunção can simply move the conflict into court without solving the underlying evidence problem.

Is an invoice an executive title?

Not normally by itself.

Portuguese enforcement requires an executive title recognised by law.

Examples include:

• condemnatory judgment;
• qualifying authenticated document;
• qualifying negotiable instrument;
• injunção with enforceability formula;
• another document given executive effect by special law.

An ordinary invoice is evidence of the claimed debt.

It is not automatically authority to seize assets.

What if the debtor acknowledges the debt?

A written acknowledgment can materially improve the creditor's evidence.

Whether it also creates an executive title depends on its legal form.

Do not assume every email saying "we will pay" has direct enforcement force.

But preserve it.

Acknowledgments can be very important in contested proceedings and settlement negotiation.

Payment plan

A payment plan can be commercially sensible if the debtor has a real liquidity problem.

Put it in writing.

Define:

• total acknowledged balance;
• interest;
• instalment dates;
• consequences of default;
• whether the full balance accelerates;
• guarantees or security if appropriate;
• legal costs;
• jurisdiction and notice mechanics.

Do not replace one uncertain debt with an equally vague instalment arrangement.

What if the debtor company appears insolvent?

Repeated excuses, closed offices or multiple unpaid creditors can signal more than one late invoice.

Before spending money on litigation, investigate:

• company registry status;
• known enforcement history where lawfully accessible;
• insolvency proceedings;
• assets;
• whether there is a realistic recovery path.

A legally valid claim and a commercially recoverable claim are not always the same thing.

What if the debtor is outside Portugal?

Jurisdiction and enforcement become separate questions.

Check:

• governing law;
• jurisdiction clause;
• debtor domicile;
• where assets are located;
• EU or non-EU enforcement framework.

Do not assume a Portuguese invoice automatically means a Portuguese court is the only or correct forum.

A practical unpaid-invoice sequence

1. Verify the debt

Contract, performance, invoice and balance.

2. Calculate interest

Use the correct legal or contractual rate.

3. Send a formal demand

Set out the debt and final payment date clearly.

4. Assess likely opposition

Is there a real contract dispute?

5. Select the procedural route

Injunção, declaratory action or direct enforcement if you already have an executive title.

6. Investigate recoverability

Especially for larger claims.

7. Preserve settlement options

A controlled payment plan can be better than an empty judgment.

Common mistakes

Treating the invoice as an executive title

Usually it is not.

Assuming injunção is capped at EUR 15,000 in every case

Qualifying commercial transactions can use injunção regardless of claim value.

Adding EUR 40 to every debt

The statutory amount is linked to qualifying commercial transactions.

Filing before understanding the debtor's defence

A contested claim needs evidence.

Winning legally but ignoring collectability

Recovery requires reachable assets.

Frequently asked questions

Can I charge interest on an unpaid B2B invoice?

Yes, where the legal or contractual conditions are met. Qualifying commercial transactions have a specific late-payment regime.

Can I use injunção for more than EUR 15,000?

For qualifying commercial transactions under Decreto-Lei n.º 62/2013, injunção is available irrespective of the debt amount.

What if the debtor objects?

The matter proceeds into the appropriate court process.

Does a successful injunção let me seize assets?

If it receives the enforceability formula, it can become an executive title for enforcement.

Is EUR 40 always recoverable?

No. The statutory EUR 40 amount is tied to the commercial late-payment regime.

What if the debtor has no assets?

You may have a valid claim but limited practical recovery. Asset and insolvency analysis can become important.

Is your Portuguese client or business customer not paying an invoice?

Send us the contract, invoice, delivery or service evidence and payment history.

Our lawyers can assess the debt, calculate the recoverable amounts, prepare the demand and choose between injunção, litigation, settlement and enforcement.