What is Turkey's İYS system?
İleti Yönetim Sistemi (İYS) is Turkey's central system for recording and managing commercial electronic messaging permissions and refusals. İYS does not send WhatsApp campaigns and is not a substitute for a guest relationship management product.
The applicable rules depend on the service provider, recipient and communication purpose. A previous booking alone does not establish permission for a new marketing invitation.
A tasting menu announcement is not a booking reminder
A restaurant may have thousands of guest numbers collected to confirm bookings. When it announces a new tasting menu or event, the purpose has changed from operating a reservation to marketing a new experience.
Before choosing recipients, identify the sending company and venue, the purpose, appropriate commercial messaging permissions and any later opt-outs.
Does a restaurant need to register with İYS?
Restaurants, hotels and other businesses that send commercial electronic messages to guests may have obligations under İYS. Which company is the service provider, whether the recipient is a consumer or a merchant, the type of message and statutory exceptions must be assessed case by case.
“The guest has dined with us before” or “we already have the phone number” is not, on its own, a legal basis for sending a commercial campaign. Check your İYS registration, brand mapping, consent sources and opt-out processes with your legal counsel.
Are a privacy notice, explicit consent and ETK the same thing?
No. Under KVKK, the controller identifies an appropriate lawful basis for processing personal data and provides a privacy notice. Explicit consent is only one of the lawful bases in the law; it is not automatically required for every processing activity. Where processing relies on explicit consent, the consent text is presented separately from the privacy notice.
ETK approval, in turn, concerns sending commercial electronic messages such as promotions and campaigns. KVKK's principle decision no. 2026/347 of 18 February 2026 specifically emphasises that the privacy notice and the explicit consent text are drafted separately and that no approval or consent is requested for the notice itself. Differences between explicit consent, ETK and KVKK explains the distinction with examples.
Is İYS alone enough for WhatsApp?
Businesses using the WhatsApp Business Platform are also subject to Meta's separate messaging policy. It matters that the guest knows which business will send which kind of messages, agrees to be contacted on WhatsApp and can send opt-out requests. Campaign messages initiated by the business are sent with Meta-approved templates that fit their purpose.
Do not assume that an ETK or İYS approval is enough for WhatsApp on its own; Meta's conditions and data processing obligations must be assessed together. Our article Is İYS registration required for a WhatsApp campaign? walks through a separate example flow.
Keep booking reminders and marketing invitations apart
Telling a guest the time and place of an existing booking is not done for the same purpose as inviting them to a new tasting menu or a discounted event. Transactional notices about delivering the service and messages containing a campaign may be subject to different rules. Adding a new offer to a message can change its nature.
Rezervem Manager handles operational communication about the existing booking; Rezervem Connect handles marketing announcements and invitation campaigns. See the difference between a service message and a marketing message.
Check before sending a campaign
Instead of messaging your old list of hundreds of records directly, re-verify the permissions at the time of sending. Do not send campaigns to guests without proof of permission or who have opted out.
- Are the sending company, brand and purpose of the communication clear?
- Has the controller provided the KVKK privacy notice and identified an appropriate lawful basis?
- Have ETK approvals, İYS records and opt-outs been checked?
- Has WhatsApp messaging permission been assessed separately?
- Does the campaign use a Meta-approved template in the correct category?
- Do permission changes and opt-out requests stop later sends?
Where do Rezervem Join and Connect help?
Rezervem Join lets a new guest create their own profile and complete the relevant permission steps through the QR code on the table or a shared link, without requiring a booking. If the venue's İYS details are set up correctly in Rezervem, a flow that supports transferring ETK approvals to İYS can be used.
Rezervem Connect is a standalone WhatsApp CRM and campaign product; Manager or another booking system is not required. Segments are prepared from Join registrations and existing guest lists whose permissions have been verified, and campaigns are managed through Meta-approved templates. Having a booking history is not a condition for a campaign.
To plan a campaign see Rezervem Connect, to see the permission collection flow see Rezervem Join, and for the steps before sending see the İYS–ETK–WhatsApp checklist.
Official sources
See the Turkish Ministry of Trade's İYS guidance, the KVKK authority's decision announcement and Meta's WhatsApp Business Messaging Policy. This is general information, not legal advice.
FOR INFORMATION ONLY · NOT LEGAL ADVICE