Frequently Asked Questions

WhichSMS is a robust communication infrastructure platform that provides developers and businesses with high-quality APIs for sending bulk SMS and secure One-Time Passwords (OTPs).

Simply create a free account on our platform. Upon registration, you will automatically receive complimentary SMS credits to test our delivery network and API integration before making a financial commitment.

We accept a variety of secure payment methods to make topping up your account easy. You can fund your API balance using Mobile Money or major credit/debit cards.

No. Account registration is completely free, and we operate on a transparent pay-as-you-go model. You only pay for the SMS credits or API bundles you purchase.

All credit purchases are final and non-refundable. We encourage you to utilize your 10 free testing credits to ensure our platform meets your requirements before purchasing larger bundles.

Our API is designed with a developer-first approach. We provide clean, comprehensive documentation that makes it simple to plug our SMS and OTP infrastructure directly into your custom applications, regardless of your tech stack.

If an API request is made to an invalid or improperly formatted phone number, the system will reject the delivery, and the credit may still be deducted depending on the carrier's routing attempt. We highly recommend validating and formatting your user numbers before initiating an API call.

Absolutely. WhichSMS is fully optimized for transactional messaging. We offer dedicated infrastructure to ensure secure, lightning-fast delivery of authentication codes and OTPs.

Yes. To maintain our high network quality and tier-one delivery rates, we strictly prohibit sending spam, unsolicited marketing, sexually explicit content, hate speech, or fraudulent/phishing campaigns. Violating these terms will result in immediate account termination.

While WhichSMS routes messages instantly, final delivery depends on the recipient's Mobile Network Operator (MNO). Delays can occasionally happen due to carrier congestion, the recipient's phone being turned off, or network outages on the operator's end.

As the user, you are exclusively responsible for the content you create, upload, and transmit through our API. You must ensure that your campaigns comply with all local and international telecommunications and privacy laws.