I gave my tax portal password to my accountant. Here's what I learned.

When I moved to Portugal and registered as a trabalhador independente (independent worker), the first thing I did was find an accountant. Everyone told me to. Portuguese tax rules are specific, the language barrier is real, and getting things wrong with the tax authority (AT) is not the kind of mistake you want to make in a new country.

My accountant was helpful. She set up my activity in the Portal das Finanças, explained which tax category I fell under, and gave me a list of expenses I could deduct. Then she asked for my login credentials to the portal.

I gave them to her. Everyone does.

The monthly routine

The workflow settled into a pattern. Every month, I'd email my accountant with the hours I'd sold, which client to invoice, and the amount. She'd issue the Recibo Verde on my behalf through the portal. Every quarter, I'd send a list of my business expenses with scanned PDF invoices attached. She'd handle the quarterly VAT declaration.

It worked. Mostly. But I had almost no visibility into what was actually happening.

The expense black box

My accountant received my expense list each quarter and declared some of them. Others she skipped. The guidelines on what's deductible for a solo entrepreneur on the regime simplificado aren't always obvious, so I assumed she knew better than I did.

She probably did. But I never got a clear explanation of why certain expenses were included and others weren't.

It wasn't until later that I understood one of the reasons. Several of my expenses were from US-based suppliers: software subscriptions, cloud services, tools I use daily for my work. These don't carry Portuguese VAT and aren't visible in the AT's e-fatura system (the portal where expenses with a Portuguese NIF show up automatically). Because they're not part of the Portuguese VAT ecosystem, they can't be included in the quarterly VAT declaration.

That part is correct. But it also means they're easy to forget. These expenses can only be declared in the annual IRS tax return, not in the quarterly cycle. My accountant correctly skipped them in the quarterly declarations, but when it came time for the annual return, they were forgotten. I didn't catch it because I never got to review the declaration before it was submitted.

The Amazon and Google problem

There's a specific edge case that tripped me up. Some US-based companies (Amazon and Google are the most common) charge Portuguese VAT on their invoices even when they arguably shouldn't, or the invoicing entity and VAT treatment don't align cleanly with how Portugal expects things to work. The invoices exist in a grey zone: they have VAT on them, but they don't fit neatly into either the Portuguese e-fatura system or the standard quarterly declaration.

Most accountants, from what I've heard, simply ignore these. They don't fit anywhere obvious, the amounts are usually small, and the effort to classify them correctly isn't worth the deduction. Which is probably fine from a practical standpoint. But as the person whose tax return it is, I didn't know this was happening until I started digging into it myself.

The 2FA incident

The Portuguese tax authority recently introduced two-factor authentication for the Portal das Finanças. A security improvement. Standard stuff.

My accountant sent all her clients an email asking them not to enable it.

Think about that for a second. The tax authority adds a security feature to protect your account, and the established workflow requires you to leave it disabled so someone else can log in as you. The portal does support sub-user accounts now, but from what I've heard from other freelancers, the permissions available to sub-users aren't sufficient for everything an accountant needs to do. So the workaround continues: share your main credentials, skip 2FA.

The declaration I never approved

Every year, the annual IRS declaration needs to be filed. This is the big one: your total income, all deductible expenses, the final tax calculation. I asked my accountant if I could review it before submission.

One year, she told me the review functionality in the portal wasn't working. Another year, the declaration was submitted and I received a copy afterward. I was told it had been accepted by the AT.

I never had a chance to verify the numbers, check which expenses were included, or understand the final calculation before it became official. And here's the part that kept nagging at me: legally, it's my declaration. My name, my NIF, my signature. If something is wrong, the AT comes to me, not my accountant.

The questions that started this

I'm not blaming my accountant. She was doing her job within a system that works this way for thousands of freelancers across Portugal. The workflow (share your credentials, email your hours, let the accountant handle it) is standard practice. It's how the profession operates here.

But it left me with questions I couldn't shake:

Who is responsible? I'm giving someone my portal login to submit declarations in my name. If those declarations contain errors, it's my tax record. The accountant has professional liability, but the tax obligation is mine. I'm trusting someone to be accurate with information that I can't easily verify.

Why can't I see what's being submitted? The monthly Recibos Verdes, the quarterly VAT returns, the annual declaration: these are all filed through my account. But the workflow doesn't include a step where I review and approve before submission. It's not that my accountant was hiding anything. The process just doesn't have a natural approval step built in.

Why don't I understand my own expenses? I send a list of what I spent. Some of it gets declared, some doesn't. The reasons aren't always explained, and the edge cases (US suppliers, non-EU expenses, the Amazon/Google grey zone) are handled silently. At the end of the year, I don't have a clear picture of what was declared and what wasn't.

These aren't complaints about one accountant. They're observations about a workflow that gives the freelancer very little visibility into their own tax affairs, in a system where the freelancer is the one legally responsible for everything that gets submitted.

Why I started building Descodify

After three years of this, I decided to do my own administration. I wanted to understand what was actually being submitted in my name. So I started learning. I read the legislation, navigated the Portal das Finanças myself, figured out how the quarterly VAT declarations worked, what Social Security contributions were based on, and how the annual IRS return was calculated.

I found that there are already some solutions in Portugal for managing this. But none of them addressed the specific complexity I was dealing with: a foreigner who arrived with existing clients abroad, invoicing in different currencies, with expenses from US and EU suppliers that don't fit neatly into the Portuguese system. The tools that existed assumed you already understood how things work here. They assumed you knew the terminology, the workflows, the rules. They were built for Portuguese accountants or for people who'd been in the system for years.

That's the gap Descodify is built for. Not to replace accountants. They understand Portuguese tax law far better than I ever will. But to give the person whose name is on the declaration actual visibility and control over what's happening.

Descodify is your digital sidekick for navigating Portuguese bureaucracy as a solo entrepreneur. It handles invoicing, expenses, VAT, and Social Security, but more importantly, it explains everything in plain language. It's built especially for people who don't know the specific Portuguese rules, don't understand the terminology, and have no idea what things actually mean or how they connect. If an expense gets excluded, you see why. If a declaration is ready to submit, you review it first. If your accountant handles the filing, you still see exactly what was filed.

You can use Descodify alongside your accountant or on your own. Either way, you see everything. You understand what's being done. And you're the one who approves it before it goes to the tax authority.

Because at the end of the day, the AT doesn't care who filled out the form. They care whose NIF is on it.

Read more about why Descodify exists and what it does.

Related: I've been invoicing my foreign clients wrong for years: the invoicing problem that started when I tried doing my own Recibos Verdes for foreign clients.

Related: I compared three years of tax declarations my accountant filed: what I found when I finally read the paperwork.