After Safaricom issues you a till number, the till number owner should get access to Mpesa portal for that till number, however, if that is not the case, then you will have to ask Safaricom to create for you a Business Admin for that till number.
You can do that by preparing a letter (addressed to Safaricom) with the below details on a company letter head, signed and stamped by top management.
Organization Short code : (Indicate your head office number for the till number here)
ID type (national ID, Passport):
Administrators User Name:
Once you have this ready, attach it with the id of the business admin and email it to : email@example.com
Have further questions, email us: firstname.lastname@example.org