Commercial Bank of Africa (CBA) customers will on Friday and Sunday not have access to some of the services as the bank makes systems upgrade.
The lender which has developed a reputation as the go-to provider for large corporations, institutions, diplomatic missions, NGOs and high net-worth private clients will be moving its systems infrastructure to a 'state-of-the-art' data centre over the weekend.
The move will ensure resilience on all their platforms and boost data recovery capabilities.
Some of the services that will be inaccessible include ATM, M-Pesa, and card transactions.
The services will be interrupted on Friday and Sunday from 1am until 5am.
"We regret the inconvenience, as we endeavour to improve our banking services and give you time for more," CEO Jeremy Ngunze said in a statement on Thursday.
CBA is among the largest privately owned banks in East Africa and has been operating for over 50 years.
It began as a subsidiary of Societe Financiere pour les pays D’Outre Mer (SFOM), a Swiss-based consortium bank.
Other consortium members included Bank of America, Dresdnen Bank (now Commerzbank), Bank Bruxelles Lambert and Banque National de Paris.