Hoiio Open API

To receive an incoming SMS, you’ll need to subscribe to a Hoiio Number that can receive SMS.

Currently, only our US Hoiio Numbers can receive SMS.

After you have subscribed to a Hoiio Number, configure the number to send a notification to your application when there is an incoming SMS.

Supported encoding are Latin-1 and GSM 7-bit. If an incoming SMS is more than 160 characters, you will receive multiple notifications each of 152 characters or less.

Note: If your account is a trial developer account, you can only receive SMS sent from your registered number. To remove this restriction, please make a credit top-up. See Free Trial for details.




You must configure your Hoiio Number to send a notification to your application via either the Developer Portal or number/update_forwarding API. When there is an incoming SMS to your Hoiio Number, a notification will be sent to the URL you specified with the following parameters:

Notification Parameters

txn_ref The unique reference ID for this transaction.
msg The content of the SMS.
from The incoming Caller ID of this SMS. Phone numbers start with a "+" and country code (E.164 format), e.g. +6511111111.
to The recipient number of this SMS (your Hoiio Number). Phone numbers start with a “+” and country code (E.164 format), e.g. +6511111111.
date Date/time (GMT+8) of this transaction in “YYYY-MM-DD HH:mm:SS” format.
currency Currency used for this transaction. Refer to Currency Code for the list of currency code.
debit Total amount billed for this transaction.

API Limits



Charges apply for SMS that are received via this API. The cost per SMS is based on your Hoiio Number. Please check the Pricing Section for details or you may retrieve the rates with sms/get_rate API.