Investors can now sign up for a stockbroking account through DBS Bank online and link it to their existing Central Depository (CDP) account.
DBS customers who already have a CDP account - where share trading funds are held - can sign up for a new trading account through Internet banking.
To start trading stocks, the trading or broking account has to be linked to the CDP account. That can now be done through DBS' Internet banking platform, too.
Previously, customers would have to visit the branch, or sign and mail in multiple sets of forms, just to open a trading account.
Mr Jeremy Soo, DBS' head of consumer banking group in Singapore, said the new service - a tie-up with Singapore Exchange (SGX) - improves the customer experience for its five million customers as everything is done "with just a few simple clicks".
To start trading stocks, the trading or broking account has to be linked to the CDP account. That also can now be done online through DBS' Internet banking platform.
It usually takes about 10 days before investors can start trading but this will be shortened to at least four days after a trading account is linked to a customer's existing CDP account.
There are 1.7 million CDP individual accounts in Singapore.
Mr Andrew Soh, head of retail business at DBS Vickers, DBS' stockbroking arm, said: "As we continue to grow our business, we are seeing an increasing convergence between stockbroking and banking.
" By digitalising the account application process, customers are now able to open a trading account online anytime, anywhere, giving them more time for the things that matter to them."
As part of the SGX collaboration, DBS has introduced a direct crediting service via SMS to allow customers to receive dividends into their designated bank accounts.
Ms Lynn Gaspar, SGX's head of retail investors and intermediaries, said: "We are supportive of industry efforts that deliver greater convenience to our retail investors and are pleased to collaborate with DBS in this first step.
"We look forward to further collaboration with other industry partners that will improve cost efficiencies for brokerage firms as well as facilitate benefits to retail investors that will ease their investing process and experience."