South Africa have already turned down PCB's request for a tri-series and the PCB officials are still waiting for a reply from the Sri Lankan Cricket on a proposed one-day series later this month.
"Our players need to play competitive cricket and with no immediate international events planned now, we thought it would be best to have the Twenty20 championship," a senior PCB official said.
The official said Pakistan's next international assignment is expected to be a four-nation Twenty20 event in Toronto in October and the national event would give the players much needed exposure and practice.
"We will ensure that all the top players make themselves available for the domestic Twenty20 event," the official said.
Asked about the Board's decision few months back to allow teams to play one or two overseas players in the Twenty20 and domestic competitions, the official said, "It would take time for this to happen as teams needed to have strong sponsorship and financial backing to sign on even one or to foreign players."