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Electricity & gas · Portugal
Checked 2026-09-30

🗓️ Estimated bills and back-billing in Portugal: how far back can my supplier charge me?

The short answer

If your meter was not read for a long time, a large catch-up bill can follow. Many countries limit how far back a supplier may charge and set rules for meter readings.

📜 The rules in Portugal

Back-billing and estimated bills

Under the essential public services law (Lei 23/96), a supplier's right to be paid for electricity expires six months after supply; if you paid too little, it can claim the difference only within six months of that payment. You must invoke this expressly, preferably in writing.

  • If an adjustment (acerto) is more than 25% of your average consumption, you automatically get a payment plan of up to 12 monthly instalments. (erse.pt)
  • Without real readings the bill is estimated. Send your meter reading to your supplier every month on the dates shown on your bill. (erse.pt)
  • For smart meters read daily, ERSE's rules say bills must use real readings; the grid operator may estimate only when there is a metering or reading fault, and must correct it within 30 days. (erse.pt)
Official source: erse.pt · Checked 2026-09-30

🪜 Step by step

  1. Read your meter nowTake a dated photo and send the reading to your supplier. It stops estimates from growing.
  2. Check the period on the billWhich months are charged, and was the reading real or estimated?
  3. Compare with the rulesSee below how far back a supplier may bill in Portugal and how often your meter must be read.
  4. Dispute in writingIf the bill goes back further than allowed, write to the supplier, then to the dispute body below.

📇 Who to contact

Centros de Arbitragem de Conflitos de Consumo (RNCAI)Settles disputes with energy companiesWhen the company has not solved your complaint🔗 www.erse.pt/centros-de-arbitragem
ERSE - Entidade Reguladora dos Serviços EnergéticosSupervises energy companies and explains your rightsFor information, and to report a company that breaks the rules📞 213 033 200🔗 www.erse.pt/consumidores-de-energia

❓ Questions

Do I have to pay a huge catch-up bill at once?

Ask for a payment plan. Many suppliers must offer one; the rules for Portugal are on this page.

Why did I get an estimated bill?

No reading was available. Send a real reading and ask for a corrected bill.

What if the meter was faulty?

Ask the grid operator to test it. Keep the test report for your complaint.

📎 Sources

Checked: 2026-09-30

🧭 Is this still correct?

We check this information carefully, but phone numbers, websites and rules change — and sometimes we get something wrong. Spotted a mistake or a change? Let us know below.

🔗 Also useful

🧾Wrong or high bill→📣Complaint about a supplier→📟Smart meter→🔄Switching supplier→📈Price increase→

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