A contact group in iSend is the recipient list that a campaign or an automation is addressed to. Each account can have as many groups as it wants, and a contact can belong to more than one. Contacts enter a group through file import, manually, from the group's signup form, or through the API from your own system. In every case the source of consent is recorded with date and time.
How to create a group
- In the Contacts menu click New group.
- Give it a name that describes who is in it, for example "E-shop customers 2026" or "October appointments".
- Save. The group is ready to receive contacts.
Each group has the basic contact fields, namely phone, first name, last name, email, company, address, salutation, date of birth and anniversary, and accepts custom fields from its settings, for example appointment date and time. These fields are what fill the personalization tags in messages and feed the automations.
How to organize customers into groups
The group is how you send the right message to the right people. Three approaches that work:
- By relationship: "Customers", "Prospects", "Partners". Offers go to customers, updates go to everyone.
- By store or service: "Thessaloniki", "Athens", or "Hair salon", "Beauty". Each group gets its own hours and offers.
- By signup source: "Signups at the register", "Signups from the website", "Import from Excel". This way you know where each group's consent comes from.
A contact that belongs to two groups of the same campaign receives the message once. Anyone who opts out with STOP is removed from all your groups at the same time, as the article on recipient opt-out explains.
Signup form per group
Each group has a public signup form, with its own link, where the customer enters their mobile number and the details you ask for. You place the link on your website, in a QR code at the store or in an email. The signup is recorded with the source "electronic consent", date and time. Likewise, the group also has an opt-out form, for anyone who wants to leave without replying to a message.
Adding contacts through the API
If customers sign up in your own system, such as a form on your site, a point-of-sale program or a CRM, one call adds the contact to the group:
POST https://sms.isend.gr/api/http/contacts/{group_id}/store
Authorization: Bearer YOUR_API_TOKEN
Content-Type: application/json
{"PHONE":"306912345678","consent_source":"electronic_consent"}
The group_id is the group's identifier, shown in the address of its page on the platform. Along with PHONE you can pass the group's other fields with their tag, for example "FIRST_NAME":"Maria" or a custom field. The consent_source states where you have consent from, with the same values that file import asks for: written_consent, email_consent, electronic_consent, verbal_confirmation, existing_customer. If omitted, "API" is recorded. If the number already exists in the group, the call returns an error with the group's name instead of creating a duplicate contact. The response contains the contact's identifier, the number, the status and the consent source. The article on the API key and the first SMS explains how to get the token.
Frequently asked questions
How many groups can I have?
As many as you need. A contact can belong to many groups, and a campaign can be sent to many groups at once without the same number receiving the message twice.
Can I move contacts from one group to another?
Yes, from the group's contact list you select the contacts and add them to another group. The contact's consent and history follow, because they belong to the contact and not to the group.
What proves that the customer consented?
Each contact's profile keeps the consent source, the date and the time, whether it came from a file, from a form or from the API. These are the details you need if you are asked for proof of consent.