The amount is double what President Donald Trump’s team has set aside which is around $147 million.
Joe Biden’s campaign is reserving $220 million in television airtime with the remaining $60 million in digital ads, based on a review of Kantar/CMAG data by The Associated Press.
Both the Trump and Biden campaigns can add to or subtract from their reservations at any time.
The buy reflects the Biden campaign's improved fundraising machine.
Along with the Democratic National Committee and joint fundraising committees, it raised a combined $140 million in July.
The committees have a total $294 million cash on hand.
Biden struggled to raise funds during the primary but has been ramping up his efforts since becoming the presumptive nominee and has worked to close the fundraising gap with the Trump campaign.
Biden is reserving airtime in 15 states, which includes a number of traditional swing states — Pennsylvania, Michigan, Wisconsin, and Florida — as well as a number of historically Republican states, including Arizona, Georgia, and Texas.