> For the complete documentation index, see [llms.txt](https://help.recart.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.recart.com/sms/subscribers-and-lists/sms-opt-in-types.md).
# SMS Opt-in Types
Explains each SMS opt-in type in Recart, which opt-in tools and messaging types it works with, and what subscribers see on desktop and mobile.
Learn which SMS opt-in types you can use on each opt-in tool, what your visitors see on desktop and mobile, and which types work in one-way messaging countries.
***
### Which opt-in type can you use?
You choose the **SMS opt-in type** when you create a popup, landing page or embedded form. The options depend on the tool and on its messaging type:
| Opt-in tool | Two-way messaging (usually US and Canada) | One-way messaging (usually outside the US and Canada) |
| -------------------------------- | ------------------------------------------------------------------------------------------------ | ----------------------------------------------------- |
| Popups (desktop and mobile) | In-Popup confirmation (default), Reply in SMS as a consent, OneClick opt-in (returning visitors) | In-Popup confirmation (default), Phone number only |
| Landing pages and embedded forms | Reply in SMS as a consent | Phone number only |
| SMS keywords | Texting the keyword | Not available |
* Desktop and mobile popups are created separately, and both offer the same opt-in types. So a desktop popup can use either the one-time code (In-Popup confirmation) or Reply in SMS as a consent.
* One-way options only appear if your account has a one-way sender, such as an [alphanumeric sender ID](/getting-started-with-recart/phone-numbers/alphanumeric-sender-ids.md). If you only have a US number, you won't see them. See [One-way vs Two-way Messaging](/getting-started-with-recart/phone-numbers/one-way-vs-two-way-messaging.md) for which applies in common countries.
{% hint style="info" %}
You can't change the SMS opt-in type later in the editor, and a duplicate keeps the type of the original. To switch, create a new opt-in tool.
{% endhint %}
{% hint style="info" %}
**Selling in the US and abroad?** Use a two-way popup for visitors in the US and Canada and a separate one-way popup for the countries you text from your brand name. Set each popup's geotargeting so visitors only see the one that fits their country.
{% endhint %}
### Double opt-in vs single opt-in
With **double opt-in**, the visitor confirms their number before they're subscribed: by entering a code, by replying to a text, or with OneClick. This keeps fake or mistyped numbers off your list, lowers the risk of spam complaints and builds trust, so subscribers are more engaged.
With **single opt-in** (Phone number only), the visitor is subscribed as soon as they submit their number. It's quick, but there's no check that the number belongs to them.
### In-Popup confirmation (one-time code)
The visitor confirms with a one-time code texted to them, without leaving your site. This is the default for popups.
* **Works with:** popups on desktop and mobile, in both two-way and one-way messaging countries.
* Because the visitor doesn't need to reply, it's the double opt-in option for popups in one-way countries.
**Desktop and mobile journey**
1. The visitor enters their phone number in the popup and clicks the button.
2. Recart texts them a one-time code.
3. The visitor enters the code in the popup.
* On mobile, many phones offer to fill in the code from the text automatically.
4. The popup shows your success step, and Recart sends the legal message and your welcome message.
### Reply in SMS as a consent
The visitor confirms by text. It only works with two-way messaging, because the subscriber has to text you.
* **Works with:** popups on desktop and mobile, landing pages and embedded forms, in two-way messaging countries.
**Desktop popup journey**
1. The visitor enters their phone number in the popup and clicks the button.
2. Recart texts them, asking them to reply Y or YES to confirm.
3. The visitor replies Y or YES from their phone.
4. Recart sends the legal message and your welcome message.
**Mobile popup journey**
1. The visitor taps the button in the popup.
2. Their messaging app opens with a pre-written text to your number.
3. The visitor sends the text.
4. Recart sends the legal message and your welcome message.
**Landing pages and embedded forms:** the visitor also confirms by text before they're subscribed.
**How replies are counted:**
* The visitor isn't subscribed until they reply Y or YES (or send the pre-written text on mobile).
* Capital and small letters don't matter, and Y! or YES! with exclamation marks also count.
* Only their first reply counts. If it isn't Y or YES, the opt-in doesn't go through.
{% hint style="warning" %}
The confirmation text is charged like any other message, at the prices in your contract. It shows under **Other** in your [SMS usage](/billing/sms-billing-explained.md). Recart blocks bot sign-ups that would trigger these texts and limits how many your site sends each day. See [Bot Filtering](/compliance-protections/built-in-protections/bot-filtering.md#bot-sign-ups-on-your-popups).
{% endhint %}
### OneClick opt-in
For returning visitors who already opted in on your store. Recart recognizes them, pre-fills their details, sends a verification code to their known number, and they subscribe with one tap.
* **Works with:** popups for visitors in the US. Needs an active Welcome Popup as the fallback.
* See [OneClick Popup](/list-growth/popups/oneclick-popup.md) for setup.
### Phone number only (single opt-in)
The visitor is subscribed as soon as they submit their phone number. No code or confirmation text is sent.
* **Works with:** popups, landing pages and embedded forms with one-way messaging.
* Because there's no confirmation step, fake or mistyped numbers can end up on your list, and the risk of spam complaints is higher.
* Phone number only isn't offered for two-way messaging. If you're in the US or Canada and want to use single opt-in, contact your Customer Success Manager or .
### SMS keyword opt-in
The visitor texts your keyword (for example, from a social post or printed flyer) to your number. Texting the keyword is their consent.
1. The visitor texts the keyword to your number.
2. Recart sends the legal message and your welcome message.
* **Works with:** two-way messaging only, because the subscriber texts you first.
* Add the compliance text wherever you promote the keyword. See [SMS Keywords](/list-growth/other-opt-in-tools/opt-in-tools-sms-keywords.md).
### Recognizing Returning Visitors
On Shopify stores, Recart recognizes returning visitors through the [Recart Pixel](/list-growth/how-recart-recognizes-returning-visitors-recart-pixel.md). Recognition typically lasts up to a year, so a visitor who opted in through your popup and comes back weeks later isn't treated as a new visitor, and your abandonment flows still reach them without them having to resubscribe.
If a returning visitor does subscribe again, they won't be counted twice in our system.
If you have any questions, do not hesitate to [contact the Recart Support team.](/contact-recart-support.md) We'd be happy to help!
---
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