From Kolmisoft Wiki
How to buy Skype credits from Digium?
1. Go to https://www.digium.com/en/login/register.php and register an account by filling these and other required field by Digium:
2. After submitting the registration you will get an email from Digium. Validate you email and activate the account by clicking the link in email. 3. Now Log in with an account details you registered with Digium:
4. Go to Digium store 5. Select how many channels you would like to buy and press “Add to Cart”:
6. If all provided information is correct – checkout:
7. Complete the transaction by paying for selected amount of Skype channels via your preferred payment method (Visa, Mastercard, American Express, PayPal are supported as of time of writing this article).
 Skype installation
After completing these steps you will see a similar output:
Now download Skype For Asterisk from http://downloads.digium.com/pub/telephony/skypeforasterisk:
Extract the archive and install:
Now check in Asterisk CLI how many licensed channels you have:
Configurations for Skype are located in /etc/asterisk/chan_skype.conf
 Skype Business Account creation
1. Create a Skype Business Account at http://skype.com/business
3. You will receive an email from Skype. Activate your Skype Business account by visiting the provided activation link in email.
 Create Skype accounts for calling
Go to https://manager.skype.com and follow the steps:
DO NOT CREATE ACCOUNTS IN ANY OTHER METHOD – THEY WILL NOT WORK WITH Skype For Asterisk