The 2026 myDATA playbook for Greek freelancers

Time tracking → invoicing → AADE, without the four-tool stack

If you're freelancing in Greece in 2026, your stack probably looks like this:

• Toggl or a notes app for tracking hours
• Google Sheets for billable summaries
• Word or a free invoice generator to create the PDF
• A separate myDATA service to transmit the document to AADE
• WhatsApp to chase the payment

Four tools, four logins, and a recurring fear that you forgot to transmit the last invoice. If the MARK didn't come through, the invoice isn't legally issued. Which means it doesn't count toward your VAT, which means you've got a problem when the next tax filing rolls around.

This guide explains what myDATA actually requires, the four-tool problem in detail, and how to collapse it into one workflow. Plain language. No accountant jargon.

What is myDATA, really?

myDATA (my Digital Accounting and Tax Application) is the AADE's mandatory electronic books platform. Since 2024, every business that issues invoices in Greece — including freelancers, sole traders, and small companies — must transmit a summary of every document they issue to AADE in real time.

The flow is:

1. You issue an invoice (sales invoice, service invoice, retail receipt, credit note, delivery note, or intra-community document)
2. A summary is generated — totals, VAT breakdown, client VAT number, document type code
3. The summary is transmitted to AADE via the myDATA API
4. You receive a MARK — a unique 15-digit registration number that legally tags the document
5. You also get a QR code — printed on the document, used for verification

Without the MARK and QR, the invoice isn't legally issued under Greek law. Doesn't matter that you have the PDF. Doesn't matter that the client paid. From AADE's perspective, the transaction doesn't exist yet.

Who has to do this?

If you issue invoices in Greece, you're in scope. This includes:

• Freelancers with a Greek VAT number (ΑΦΜ)
• Sole traders (ατομικές επιχειρήσεις)
• Limited companies (ΕΕ, ΟΕ, ΙΚΕ, ΑΕ, ΕΠΕ)
• Non-profits issuing receipts for services
• Anyone receiving income that requires a tax document

The only people NOT in scope are individuals issuing no invoices (e.g., employees on payroll, who get paid via their employer's monthly book entry).

The data you have to send (and when)

For each issued document, AADE requires:

Field	What it is
Document type code	1.1 sales invoice, 2.1 service invoice, 11.1 retail receipt, 5.1 credit invoice, 9.3 delivery note, 8.4 intra-community
Counterparty VAT number	Validated against VIES for EU clients
Issue date + serial	When you issued it + the document's serial number (ΑΑ)
Net amount	Total before VAT
VAT breakdown	Amount per VAT rate (24%, 13%, 6%, 0%)
Total	Net + VAT
Currency code	Almost always EUR
Country code	Where the client is based

Timing: "Real-time." AADE has tightened the window every year. As of 2026, the practical expectation is transmission within minutes of issuance, not hours. Bulk monthly uploads were phased out in 2024.

The four-tool problem

A typical Greek freelancer's invoicing flow in 2026 looks something like this:

Tool 1: Time tracking

You're billing by the hour for at least some clients. You need to track actual hours per project to know what to invoice. Most freelancers use Toggl, Harvest, or a notes app.

Typical cost: free tier or a small monthly fee for the paid tier, depending on the tool. Bigger hidden cost: the mental overhead of starting/stopping timers and remembering which client a session was for.

Tool 2: Client + project records

Where's the client's VAT number? Their billing address? Their hourly rate? Whether they pay net-30 or net-60? This lives somewhere — usually a spreadsheet, sometimes a CRM, often the freelancer's memory.

Typical cost: free if it's a Google Sheet, monthly subscription if it's a CRM tool.

Tool 3: Invoice creation

You convert tracked hours into a professional PDF invoice. Templates in Word, free invoice generators, or a dedicated tool like Invoice Ninja or FreshBooks.

Typical cost: free for basic generators, monthly subscription for dedicated invoicing tools.

Tool 4: myDATA transmission

You take the issued invoice's data and transmit the summary to AADE via myDATA. This requires either an accountant who handles it for you, a dedicated myDATA service, or direct API integration. The accountant route is the most common in Greece.

Total: 4+ logins, no single source of truth

And critically — no automatic link between the tools. Hours tracked in Toggl don't auto-populate the invoice tool. The invoice tool doesn't know your VAT compliance status. Your accountant has to ask you for the data every month.

This is why so many freelancers end up sending invoices late, missing myDATA transmissions, or just outsourcing the entire thing to their accountant — even at low invoicing volume where the cost doesn't really justify it.

What a unified workflow looks like

The cleaner approach: one tool that handles all four steps and automatically transmits to AADE.

Step 1: Track time inside the tool

Start a timer, tag it to a project, the hours get logged automatically with your client + hourly rate already attached.

Step 2: Convert hours to an invoice

Select the time entries you want to bill. The tool generates a PDF invoice with:

• Your details (logo, VAT number, address)
• Client details (auto-pulled, including their VAT number)
• Line items from the tracked hours
• VAT calculated automatically
• Your invoice serial (auto-incremented)

Step 3: Issue the invoice → auto-transmission

You click "Issue." In the background:

• The PDF is generated
• The transaction summary is built to AADE standards
• The summary is transmitted to myDATA
• The MARK comes back (typically <2 seconds)
• The QR is generated and appended to the PDF

Step 4: Send to client

The PDF is now legally issued. You email or send it. The client sees a professional document with the MARK and QR — same as they'd see from any AADE-compliant business.

Step 5: Online payment (optional)

If the tool integrates with Viva or Stripe, the invoice includes a "pay now" link. Client pays online. The payment gets reconciled to the invoice.

A worked example: e-Timologio

We've been recommending e-Timologio — e-timologio.com to freelancers in our Greek network specifically for this end-to-end flow. It collapses all four tools into one workflow and handles AADE myDATA transmission automatically.

How e-Timologio handles each piece:

1. Time tracking: One-click timer with live seconds. Per-project hourly rates. Multiple projects/clients.
2. Client records: Built-in CRM with VAT number, billing details, history. VIES validation for EU clients (auto-fills client details from VAT number).
3. Invoicing: Convert tracked hours to professional PDF invoices in seconds. Saved products/services for non-time-based billing. Multi-currency support.
4. myDATA transmission: Automatic. Average transmission time under 2 seconds. 100% document compliance. MARK and QR appear on every PDF.
5. Document types supported: All the AADE document codes — 1.1, 2.1, 11.1, 5.1, 9.3, 8.4.
6. Online payments: Viva Smart Checkout integration — your client can pay the invoice online via the link on the PDF.

The free plan includes time tracking, projects, clients, and invoicing — no credit card required. You only upgrade when you need higher volume or advanced features.

Try e-Timologio free at e-timologio.com →

(Full disclosure: e-Timologio is built by an independent Greek team in our extended network. We're including them because the alternatives we've tested either don't handle myDATA properly, charge meaningfully more for the AADE integration, or require you to keep using a separate time tracker.)

Is e-Timologio safe / legit / compliant? Quick FAQ

Is e-Timologio AADE-compliant? Yes — e-Timologio transmits directly to the AADE myDATA platform in real time. Every issued document receives a MARK and QR. 100% document compliance for the supported document types (1.1, 2.1, 11.1, 5.1, 9.3, 8.4).

Is e-Timologio free? Yes for the entry tier — time tracking, projects, clients, and invoicing are included on the free plan with no credit card required. You only upgrade when you need higher volume or premium features.

Where is e-Timologio based? Greece. Built specifically for Greek freelancers and small businesses, with a Greek-language UI option, EUR/multi-currency support, and direct AADE integration. Useful anywhere, but designed for the local rules.

Can e-Timologio handle VIES validation? Yes — when you add a client with an EU VAT number, e-Timologio validates against the VIES database and auto-fills the client's registered name + address. No more manual lookup.

What happens if AADE rejects a transmission? You see the status in real time inside the app ("Sent to AADE" → "MARK received" or "Rejected"). If rejected, you can correct the data and re-transmit. No silent failures.

Can I export my data? Yes. Full export of clients, projects, time entries, invoices, and expenses — anytime. No data lock-in.

Does e-Timologio replace my accountant? No. Your accountant still handles your tax filings (E3, FPA returns, payroll if you have staff). e-Timologio replaces the paperwork stack between you and your accountant — they receive clean, AADE-tagged invoices instead of a Google Sheet to clean up.

What to do this week

If you're already invoicing in Greece, run this audit:

1. Open your most recent invoice. Does it have a MARK on it?

If no — you might be issuing documents that aren't legally registered with AADE. This is a problem for your VAT filing. Fix this first.

2. Time how long it takes to issue an invoice end-to-end

From "I need to bill this client" to "the PDF is in their inbox AND transmitted to AADE." Most freelancers we audit clock at 25-40 minutes. With a unified tool, this drops to 3-5 minutes.

3. Add up your invoicing-stack costs per month

Toggl + Sheets + Invoice tool + accountant's myDATA fee + email sending tool. Add them up — most freelancers are surprised how much the fragmented stack costs once they look. A single unified tool is almost always cheaper AND faster. Check e-Timologio's current pricing page for the latest plans (free tier with no credit card required is enough to evaluate).

More on building a freelance presence that gets you found

Compliant invoicing keeps you legal. A clean bio page is how new clients find you in the first place. If you're a freelancer in Greece, your bio link is doing more lead-gen work than you think — especially the custom-domain version:

---

Try the alternative: e-Timologio at e-timologio.com — time tracking + invoicing + automatic AADE myDATA transmission, free to start.

---

Quick quiz: what's your myDATA compliance gap?