Frequently asked questions about bulk SMS, the WhatsApp Business API and Telegram

At SMSverifica an SMS to Spain costs €0.039 per message of up to 160 characters, with no fees and no lock-in. The Spanish market ranges between €0.029 and €0.08 depending on volume and provider. With our prepaid model in euros you only pay for what you send and you can check the rate for each country by prefix in SMS prices by country before sending.

No, never. Your prepaid balance remains available with no expiry date. On other platforms the balance does expire: 18 months at LabsMobile, according to its terms published as of July 2026, and 15 at another Spanish platform. We compare this in detail in the LabsMobile alternative and the Esendex alternative (in Spanish).

Our price per message, by conversation category: service €0.005, utility €0.005, authentication €0.005 and marketing €0.005, with no monthly fee for the line and no set-up cost. Meta bills its conversation fees separately, to your own WhatsApp Business account, and to enable the channel you need a business account verified by Meta and a number of your own (Meta approves it and it usually takes several days). More details in WhatsApp Business API.

€0.010 per message, almost four times less than an SMS to Spain. Telegram does not charge for messages sent by a bot, so that price is only our platform's. It is ideal for frequent notices, system alerts and internal notifications. Find out how in Telegram for business.

No. SMSverifica works with a prepaid balance in euros, no subscription, no lock-in and no minimums. You top up whenever you like and the balance never expires. We break down plans with a monthly fee and their break-even point in the Esendex alternative and the Instasent alternative (in Spanish).

You top up from the dashboard by card through a secure payment gateway. Every top-up automatically generates a Spanish invoice with VAT and sequential numbering, downloadable as a PDF: perfect for your accountant. You can also enable automatic top-up by threshold so you never run out of balance in the middle of a campaign.

The API is Meta's official interface for connecting WhatsApp to your software, CRM or ERP: approved templates, bulk sending, multiple agents and automation, without a mobile phone. The WhatsApp Business app is free but limited to one device and to broadcasts of 256 contacts; the API is paid, has none of those limits and can be integrated with our REST API.

They are messages with variables ({{1}}, {{2}}…) that Meta reviews and approves before you can send them to start a conversation outside the 24-hour window. They are classified by category (marketing, utility, authentication), which determines their price per message. Approval usually takes from minutes to hours, and you manage templates and variables from the dashboard.

When a customer writes to you, a 24-hour window opens in which you can reply with free text at a reduced cost (service category). Once the window has passed, you can only start a conversation with an approved template. SMSverifica checks the window automatically: if you try free text outside it, the API returns a clear error (wa_outside_window) instead of failing silently.

Yes. Meta's policies require the user's prior opt-in to receive messages from your company, and the GDPR and the LSSI require consent for commercial communications. Record the consent (website, form, ticked box) and always offer a simple way to opt out. We go into this further in the GDPR and LSSI guide for messaging (in Spanish).

Create your account, copy your API key (format sk_live_…) from the dashboard and make a POST /api/v1/messages with the X-Api-Key header and a JSON with channel, to (in E.164 format, +34…) and body. The response includes the message id and its status. With sandbox mode you test the call at no cost and without sending real messages:

curl -X POST https://app.smsverifica.com/api/v1/messages \
  -H "X-Api-Key: sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"channel":"sms","to":"+34612345678","body":"Hola desde la API"}'

It is a unique key you send in POST /messages. If the request is repeated (network timeout, a retry in your code), the API detects the key and returns the original response instead of sending and charging for a second message. As of July 2026 no other provider analysed —not even Twilio— documents idempotency on sending: we compare this in the Twilio alternative (in Spanish).

Every status change (message.sent, message.delivered, message.failed, message.read…) is sent to your URL with an HMAC signature calculated with your secret. By verifying it you guarantee that the notification comes from SMSverifica and has not been tampered with —something no Spanish provider offered as of July 2026—. If your server does not respond, we retry with increasing backoff and you can check the webhook delivery log in the dashboard.

Sandbox mode simulates the complete cycle of sending and delivery without using balance or sending real messages: ideal for developing your integration, testing webhooks and validating templates. It is enabled per account and needs no card. Start with the sandbox →

The API responds with HTTP code 402 (insufficient_balance) and the message is not sent: there are never sends into the negative or surprises on the invoice. Enable automatic top-up by threshold and low-balance alerts so your sends are not interrupted.

Each account has its own limit of requests per minute (60 by default), which can be raised according to your use case: ask for it from the dashboard or via contact. If you exceed it, the API responds 429 and you simply retry; with Idempotency-Key the retry is safe and without duplicates.

As long as the review takes. A person looks at every sign-up (company, intended use) as an anti-spam filter, and we would rather not publish a timeframe we cannot commit to. You will receive an email as soon as your account is active; in the meantime you can already explore the dashboard.

Yes. Registration is free and sandbox mode lets you test the API, the dashboard and the webhooks without entering a card and without spending balance. You only pay when you decide to top up to send real messages. Create your free account.

Yes. SMSverifica is a sister platform of QRACCESO (QR access control for events, with ticket validation and capacity control) and of ACCESSTIME (working-hours records). Typical cases for that combination: sending the QR ticket or accreditation by WhatsApp or SMS, notifying the host when their visitor arrives at reception, single-use access codes by SMS and automatic notices to employees who have not clocked in or HR reminders. All from the same account and the same balance. See the combined use cases →