Foreign nationals arriving in Türkiye discover quickly that the country runs on a number. Almost every interaction with an institution — a bank, a notary, a mobile operator, a hospital, a landlord — begins with a request for one. Without it, a surprising amount of ordinary life is simply unavailable. This article explains the two numbers that matter, which one you need for what, and how to obtain each.
Two different numbers
Confusion here is universal, and it is worth resolving at the outset because the two numbers do different things.
The foreigner identification number (YKN) is an eleven-digit number beginning with 99, assigned to foreign nationals who hold a residence permit. It is printed on the residence permit card and functions as the holder's identity number in Türkiye — the equivalent of the citizen's identity number.
The potential tax identification number is a number issued by the tax administration to a foreign national who needs to carry out a transaction with tax consequences. It does not require a residence permit and can be obtained online in minutes.
The practical rule: the tax number opens the door to transactions; the YKN comes with residence and opens almost everything else.
What you can do with a tax number alone
More than most people expect, which is why the potential tax number is the first thing an incoming investor should obtain.
- Buy property. The land registry requires a tax number, not a residence permit.
- Open a bank account. Banks can open accounts for non-residents on a passport and tax number, though individual banks apply their own compliance requirements and some ask for more.
- Establish a company and be registered as a shareholder.
- Pay taxes and fees arising from any of the above.
- Deal with a notary for many transactions.
Obtaining it is straightforward: through the Interactive Tax Office online, or at any tax office with a passport. There is no fee and no waiting period.
What requires the YKN
Once a person is resident rather than transacting, the YKN becomes the reference for daily life:
- Address registration and everything that depends on it.
- Utility subscriptions — electricity, water, gas, internet — in the resident's own name.
- A Turkish mobile line on a contract rather than a short-term tourist arrangement.
- Health services, including SGK enrolment where eligible and treatment at state hospitals.
- School enrolment for children.
- Driving licence exchange or application.
- e-Devlet, the state's online services portal, which becomes the practical interface for a large number of processes.
- Employment registration with the social security institution.
Institutions ask for it reflexively. A person without one spends a great deal of time explaining themselves at counters.
Where the difficulties actually arise
Banking. Legally a non-resident can open an account with a passport and tax number. In practice, compliance departments differ, and some branches will insist on a residence permit or on additional documentation. This is not a legal barrier so much as an institutional one, and the response is usually to approach a different bank or a branch experienced with foreign clients — or to have a lawyer open the account under a power of attorney containing explicit banking authority.
Mobile lines. Foreign nationals may register a line, and a foreign handset used in Türkiye beyond a limited period must be registered and a fee paid or it is blocked from the networks. This catches long-stay visitors who assumed their phone would simply keep working.
Utilities. Subscriptions generally require the YKN and a lease or title deed. Where a tenant cannot subscribe, bills remain in the landlord's name — which then causes problems evidencing residence at that address for a permit application.
That last chain is worth noticing. No YKN means no subscription; no subscription means weaker evidence of residence; weaker evidence means a harder permit application. Small administrative gaps compound.
Getting the YKN
The YKN is not applied for separately. It is assigned when a residence permit is granted and appears on the card. The sequence is therefore: lawful entry, residence permit application, permit granted, number assigned.
The number stays with the person. It does not change on renewal, on a change of permit type, or on a move between provinces. Where a person later acquires Turkish citizenship, they receive a citizen's identity number and the YKN ceases to be the operative reference — a transition that occasionally requires records to be updated at institutions that still hold the old number.
The order that saves time
For an investor or a new arrival, the efficient sequence is:
- Tax number — immediately, online or at a tax office.
- Bank account — on the passport and tax number.
- Transaction — property purchase, deposit, company formation.
- Residence permit application — on the appropriate ground.
- YKN — assigned with the permit.
- Address registration, utilities, mobile line, e-Devlet — once the YKN exists.
Attempting this in a different order is the source of most of the frustration people report. Someone who tries to open a bank account before obtaining a tax number, or to subscribe to utilities before holding a permit, will be turned away — not because anything is wrong, but because the prerequisites run in a fixed order.
A note on documents and consistency
One recurring administrative problem deserves mention: the spelling of names. Turkish records will carry the name exactly as it appears in the passport, and transliteration from another alphabet can produce variations between documents issued at different times or by different authorities.
A mismatch between the name on a bank record and the name on a title deed, or between a marriage certificate and a passport, creates work at exactly the moment when it is least welcome. Where variations exist, they should be identified early and, where necessary, addressed by a formal correction rather than explained repeatedly.
Frequently asked questions
Can I get a tax number online from abroad? Yes, through the Interactive Tax Office, on the strength of passport details.
Do I need a residence permit to buy property? No. A tax number is required; a residence permit is not.
Can I open a bank account without a residence permit? Legally yes; bank policies vary. A lawyer acting under a suitable power of attorney is the reliable route.
Does the YKN expire? The number stays with the person; the permit that carries it has an expiry date.
What happens to my YKN if I become a Turkish citizen? You receive a citizen's identity number, and records at institutions may need updating.
Can I use my YKN abroad? It is a Turkish identifier for use in Türkiye.
I have a tax number and a YKN — which do I give? Give the YKN where you are identifying yourself as a resident; the tax administration will link the records.
Practical help
None of this is complicated, and all of it is sequential. The people who struggle are those who arrive, attempt three things in the wrong order, and conclude that the system is impenetrable.
Dural Hukuk obtains tax numbers, opens bank accounts under power of attorney, prepares residence permit applications and handles the administrative registrations that follow, for clients inside and outside Türkiye. Call +90 535 260 74 54 or use the contact form on this site.
This article is general information on Turkish law and administrative practice as at August 2026 and is not legal advice. Institutional requirements vary; obtain advice on your own circumstances.