We are in the middle of the third-quarter tax return season. During these weeks of October, while SMEs and the self-employed focus on gathering invoices and balancing their accounts, the tax authorities do not stop. In fact, the start of autumn usually coincides with a wave of information requests, limited checks, electronic notifications and automated warnings from the Spanish Tax Agency. 📬
At Ruiz & Asociados we often see how small administrative slips or procedural errors lead to severe penalties, not because of the seriousness of the underlying issue but because an electronic notification was not answered in time. In 2026, when digital communication with public authorities is mandatory for all companies and most professionals, keeping tight control over the single enabled electronic address (DEHú) is a vital operational requirement.
⏱️ The legal fiction of notification: the clock runs even if you do not open it
Many business owners wrongly assume that an administrative notification has no effect until someone clicks the link and downloads it with their digital certificate. Nothing could be further from the legal reality.
Under Law 39/2015 on the Common Administrative Procedure and current tax rules, the electronic notification system works on the principle of presumed rejection:
- 10 calendar days: from the moment the AEAT or any other public body places a notification in the company’s electronic mailbox, there is a strict period of 10 calendar days to access it.
- Rejected (but served) notification: if 10 days pass without anyone accessing the mailbox, the notification is legally deemed rejected and served for all purposes.
- Start of the period to respond: from day 11, the legal deadlines (usually 10 or 15 working days) to respond, provide documents or appeal start running, even though the company does not know what the request says.
LIFE CYCLE OF AN ELECTRONIC NOTIFICATION
┌────────────────────────────────────────────────────────────────────────┐
│ DAY 0 DAYS 1 to 10 DAY 11 │
│ │─────────────────────│─────────────────────────────────│ │
│ Placed in the Period to access Notification │
│ DEHú mailbox and download it deemed served │
│ (deadline starts) │
└────────────────────────────────────────────────────────────────────────┘
⚠️ Consequences of ignoring the tax mailbox in autumn
Not knowing about a request does not exempt you from complying with it. The immediate consequences of letting electronic notifications lapse include:
- Losing the right to be heard: failing to provide the invoices that prove an expense is deductible, leading to the automatic cancellation of the deduction in the Q3 tax closing returns.
- Enforcement orders and surcharges: a provisional assessment becomes a final enforceable debt, with surcharges of 5%, 10% or up to 20% plus late-payment interest.
- Precautionary seizure of bank accounts: automatic freezing of current account balances or of amounts owed by customers through seizure orders addressed to third parties.
- Penalties for obstruction: fixed fines for not answering information requests, ranging from €150 to €600 in the mildest cases and increasing for repeat offences.
🛠️ Prevention tools: courtesy days and electronic power of attorney
To prevent a business trip, holidays or a peak in workload from turning into an administrative penalty, the rules provide protection mechanisms that every company should activate:
Requesting “courtesy days”
Individuals and companies included in the enabled electronic address system can choose up to 30 calendar days per year during which the Tax Agency cannot place notifications in their mailbox.
- They must be requested at least 7 days in advance through the e-office.
- They are essential for planning office closures or summer periods without surprises.
Electronic power of attorney for your advisers (Registry of Powers of Attorney)
The safest way to make sure you receive every notice is to formally authorise a specialised professional firm. By registering the power of attorney (GENERALNOT procedure), tax advisers receive simultaneous copies and immediate alerts of every communication issued by public bodies.
Accounting technology and automatic alerts
Relying only on the warning email sent by the AEAT is risky, as these emails often end up in spam or are overlooked. Modern accounting technology connected to the DEHú by API makes it possible to monitor notifications from several bodies (Tax Agency, Social Security, local councils, DGT) every day from a single dashboard.
🛡️ Correcting errors and late appeals
If you check your mailbox and find that the deadline to answer a request has passed or that a penalty procedure has started automatically, do not give up.
There are legal routes to challenge defective notifications or request the annulment of proceedings if the authorities have made procedural errors. And when the problem stems from a previous error or omission in the returns, you can rely on the right to make mistakes or file supplementary returns to reduce the impact of possible penalties.
To check the status of your notifications or request electronic powers of attorney, you can access the official Single Enabled Electronic Address (DEHú) platform or the e-office of the Spanish Tax Agency.
🏢 Ruiz & Asociados: continuous tax monitoring and protection
At Ruiz & Asociados we have spent more than three decades protecting the legal certainty and peace of mind of SMEs, large companies, the self-employed and startups. 🤝
We offer a comprehensive service of representation and daily monitoring of official electronic mailboxes. Our tax team receives, analyses and answers any request from the authorities on time and in the correct form, filing the appeals and submissions needed to defend your business.
Are you sure your DEHú electronic mailbox is up to date and properly monitored? At Ruiz & Asociados we take care of your notifications. Contact our firm today and stop worrying about administrative deadlines. 🚀
