Turkey's e-Defter requirement: who needs it, how to start.

e-Defter is the electronic version of the classic accounting books required by Turkish tax law. For many companies it's no longer a choice — it's an obligation. Who's in, and how do you start?

April 20, 2026 7 min read Finance

What is e-Defter?

e-Defter is the electronic recording of the daybook (journal) and general ledger, with monthly digital reporting to Turkey's Revenue Administration (GİB).

Unlike traditional paper books, there's no notarization or binding. Instead, an electronic "berat" (digest) is sent to GİB each month — digitally signed and hashed.

Mandatory thresholds (2026)

Each year GİB pulls new classes of company under the e-Defter requirement. As of 2026:

e-Fatura users are automatically required to use e-Defter as well.
Companies with gross sales exceeding TL 5M in the previous year, starting from the next year.
Certain sectors (fuel, tobacco, some professions in cities with population 50,000+) — no revenue threshold required.

Thresholds change annually. For the definitive list, ask your accountant; the information in this article does not constitute legal advice.

How to apply

Step by step:

Obtain a financial seal. Depending on company type, from TÜRKTRUST or another financial signature provider. Takes 1-2 weeks.
Apply via the e-Defter portal. Fill out the form at edefter.gov.tr. Your accountant submits it to GİB.
Pick software. Generating XBRL-format books manually is nearly impossible — a compatible accounting system is required.
Run a test submission. The first few months can be tested in GİB's sandbox. Errors get caught here.
Go live. From the official start date, you submit the berat each month.

Software choice

e-Defter-compliant software in Turkey falls into three categories:

1. Traditional accounting software: Logo, Mikro, Eta. The e-Defter module is purchased separately.

2. Cloud-based solutions: Paraşüt, Bizim Hesap, Logo İşbaşı. Web/mobile UI, subscription model.

3. Vertical software: Specialized for specific industries (e.g. e-Defter Pro, Atelier e-Defter).

Options in the Onremo Store

In the Onremo Store, Hesap Atölyesi e-Defter is the most popular pick. Built by Hesap Atölyesi, a team with an accounting background, targeted at SMBs.

Advantages: one-click access via Onremo SSO, automatic integration with e-Fatura (invoices flow into book entries automatically), Turkish support.

One-time $200, no monthly platform fee.

Working with your accountant

Does e-Defter make your accountant's job easier or harder? Used correctly, easier: book entries are automatic, errors decrease.

But there are friction points:

If your accountant still prefers their own software, pick a system compatible with theirs.
If invoices are entered into the system manually, your accountant may wonder what they're for. Answer: cross-check, reporting, audit prep.
Run a parallel period in months 1-2 — old method and new method simultaneously. Month 3, switch to the new only.

Common mistakes

Mistake 1: Leaving it to the last day. Preparing the month-end berat on the last day — with incomplete data — leads to submission errors.

Mistake 2: Forgetting the financial seal. You install it on the office computer; when you try to generate a berat from another machine, you're stuck.

Mistake 3: Not backing up. e-Defter files must be retained for 10 years. If the computer fails, you have a problem.

Mistake 4: Not verifying hashes. GİB may accept the berat, but errors in the content surface during an audit.

Next step

If you're uncertain about e-Defter, get professional help from your accountant or a specialist like Hesap Atölyesi.

To see compatible systems in the Onremo Store, go to the Store and filter by the "Finance" category.