Banking

How do I automate IBAN and intrabank transfers?

I'm building a solution in Africa to automate money transfers between accounts in different banks (IBAN) and accounts in the same bank. This is because I'm working on a startup whose business model requires is to have accounts in different banks (wherever it has customers), to transfer money between those accounts (so they all have the same balances) and to transfer money to customer accounts instantly (in same bank). It's a tedious process to do this manually (go to bank, fill forms, wait 3+ days). I assume banks have software to do this, but any research I've done about IBAN and bank transfers only talks about the regulations and "how the process works" and technically (platforms, OS, APIs, security, requirements, PCI, etc). Is it at all possible for an external party (not a bank) to make an automated transfer from its accounts to other accounts locally or between banks? PS: I understand my questions shows how little in know of the industry, and I'm aware how much research lies ahead, so please bear with me.