What is the maximum SMS message length?

Question

I am wondering what is the maximum SMS message when sent through Clickatell API for English and for Spanish message?

No sure if there is a difference between English

Answer 1

From the SMS wikipedia page:

Messages are sent with the MAP MO- and MT-ForwardSM operations, whose payload length is limited by the constraints of the signaling protocol to precisely 140 octets (140 octets = 140 * 8 bits = 1120 bits).

Depending on which alphabet the subscriber has configured in the handset, this leads to the maximum individual short message sizes of 160 7-bit characters, 140 8-bit characters, or 70 16-bit characters.

To your question:

No sure if there is a difference between English and Spanish, since Spanish may contain Unicode characters?

No, there is no difference, as both English and Spanish are completely covered in the 8-bit Latin 1 character set.