Blog
Guides and comparisons on SMS gateways, SMS APIs and one-time codes, written for developers and teams in Europe.
SMS order notifications in Shopware 6: plugin, templates and the Flow Builder route
SMS order notifications in Shopware 6: the TopSMS plugin, which order states to notify, ready texts with placeholders, and the Flow Builder webhook alternative.
SMS notifications for Shopify without an app: Shopify Flow or Make with the TopSMS API
There is no TopSMS app for Shopify. Here is the honest route to SMS order notifications: Shopify Flow or Make calling the TopSMS API, with example payloads.
SMS or WhatsApp Business? A neutral comparison for businesses in Germany
SMS or WhatsApp Business for customer messages in Germany: reach, opt-in rules, pricing models, template approval, delivery without an app and GDPR compared.
Appointment reminder SMS: 17 ready templates under 160 characters, and when to send them
17 appointment reminder SMS texts for practices, physio, salons, workshops, restaurants and B2B, each under 160 characters, with timing, send_at and opt-out.
SMS gateways for Germany compared (2026)
Eleven SMS gateways for German businesses compared: price per SMS, monthly fee, sender name, free trial, API and EU hosting. Prices checked November 2026.
What does an SMS cost a business in Germany? Price drivers and worked examples
What a business SMS to Germany really costs: termination fees, routes, segments, Unicode, monthly fees vs prepaid, with worked examples for 1,000 to 50,000 SMS.
Alphanumeric sender ID in Germany and Austria: how your company name gets onto the recipient’s phone
How alphanumeric sender names work on German and Austrian networks: 11 characters, GSM alphabet, no replies, no registration, and how to set the name by API.
SMS, GDPR and § 7 UWG: what German businesses must observe for transactional and marketing messages
Legal basics for business SMS in Germany: transactional vs marketing, consent and double opt-in under § 7 UWG, opt-out, sender identification, GDPR and the DPA.
How to choose an SMS gateway for your business (and which fees to watch out for)
The price per SMS is only half the story. Sender ID fees, expiring credit and “from” prices: what to ask when choosing an SMS gateway for your company.
How to integrate an SMS API: step-by-step guide in 5 minutes
Connect an SMS API to your app: account, API key, first SMS via REST and delivery reports by webhook. Examples in curl, PHP, Node.js and Python, no SDK needed.
OTP via SMS: a secure implementation, and when to choose TOTP or a passkey instead
Implementing one-time codes via SMS: generation, hashing, rate limiting, TTL, code in PHP, Node.js and Python. Plus SMS vs TOTP vs passkey, SIM swap and NIST.
How many characters fit in an SMS? Length, Unicode and multipart messages
One SMS holds 160 characters, or 70 once a single emoji or non-GSM character appears. How segments are counted, which characters cost two, and how to send more.