General top-up limits are imposed by operators and are calculated as how much credits can the receiver number get in a certain gap of time.
The limitations are :
01 Day => max 100 USD
07 Days => max 150 USD
30 Days => max 200 USD
There is also a certain number of top-ups that can be sent within a certain time frame to one number:
01 Day => 10 top-ups
07 Days => 15 top-ups
30 Days => 40 top-ups
Only exceptions to these rules are Egypt and Cameroon , please check separate announcements for these two countries.