Twilio has upgraded its Short Codes in the US, Canada, and UK to 100 messages per second (MPS) from their previous default rate of 30 MPS. This increase allows for faster sending of high-volume messages, which is ideal for applications such as marketing, alerts, and two-factor authentication. Long codes are not suitable for high-volume messaging due to carrier restrictions, while Twilio automatically queues long code messages in the US at a slower rate to ensure compliance. Existing short codes have been upgraded to 100 MPS at no extra cost, enabling customers to send more messages quickly and efficiently.