Packages are sorted on a conveyor belt at a FedEx facility in Marietta, Ga. (David Goldman/AP)

As more of our shopping moves online, the holiday season is only getting busier and more high-pressure for FedEx.

The shipping giant said in projections released Monday that it expects to handle 317 million packages between Black Friday and Christmas, a record-breaking volume that would represent a 12.4 percent increase over the last holiday season.

The company predicts that its network will be especially busy on Cyber Monday, the annual blitz of online-only deals, as well as on the first two Mondays in December. On those days, FedEx expects to handle more than double the number of packages it handles on an average day.

FedEx’s expectations for a bigger-than-ever holiday package volume are consistent with how the retail industry is planning for the holiday. Many large retailers have shifted their holiday hiring plans this year, focusing less on seasonal store associates and more on building a team of temporary warehouse workers who can pick and pack a crush of online orders. E-commerce giant said last week that it plans to hire more than 100,000 seasonal workers this year, a sharp increase over the 80,000 employees it brought on last year for the holidays.

Some of the expected increase in package volume simply reflects our general shift to shopping on our tablets and smartphones. But, particularly during the holiday season, retailers will be pulling out all the stops to make it especially convenient and desirable to shop online. Best Buy, for example, has announced that it is offering free shipping on all online purchases made during the holiday season, a change from its strategy last year, which allowed for free shipping only on orders over $35.

FedEx says it has made $1.6 billion in investments in its ground shipping service this year to increase capacity and add automation to its vast network. These efforts are probably intended to avoid the spate of bad publicity that FedEx and its chief rival, UPS, experienced after the 2013 holiday season, when they failed to deliver millions of packages in time for Christmas.

Shipping experts have said that much of the responsibility for the late packages probably fell on the retailers, which may have underestimated how many packages they would be putting through various shipping networks at the last minute or may have gambled on sending things via ground shipping instead of a more expedited format. Last year, hoping to avoid a similar situation, FedEx and UPS beefed up their seasonal workforces and worked with retailers to get earlier and better estimates of how pressured their shipping network would be.

This year, FedEx plans to hire 55,000 seasonal workers, a 10 percent increase over last year. UPS has not announced its volume projections for the season but has said it plans to hire about 95,000 temporary workers, roughly the same number as last year.

The National Retail Federation predicts that the industry will see a 3.7 percent increase in sales this holiday season, with even stronger growth — 6 to 8 percent — in the online channel.

(Amazon’s chief executive, Jeffrey P. Bezos, owns The Washington Post.)

Read more:

Holiday retail sales forecast a bit less merry this year

Retailers begin staffing up for the holiday

BB-8: The breakout ‘Star Wars’ toy that could be a big hit this holiday