AT&T customers may be the first to get their hands on the Samsung Galaxy S4 smartphone in the United States, but T-Mobile buyers may suffer a wait. While the "uncarrier" originally planned to begin online sales of the Galaxy S4 smartphone on April 24th, T-Mobile now says that online availability has been delayed five days to April 29th as a result of an unexpected inventory delay. Amusingly, it was also an unexpected inventory allotment which allowed AT&T to begin its early preorder deliveries, but perhaps it's just a coincidence.

As far as we know, T-Mobile will still begin selling the Galaxy S4 at physical retail locations on May 1st. Sprint will sell the Galaxy S4 on April 27th, and Verizon has yet to commit to a date. Read T-Mobile's apology below:

We know customers are really looking forward to getting their new Samsung Galaxy S4 soon. However, due to an unexpected delay with inventory deliveries, the Galaxy S4 will not be available on www.T-Mobile.com as planned on Wednesday, April 24. Instead, online availability is expected to begin on Monday, April 29. We apologize for any inconvenience and are working with Samsung to deliver the device to T-Mobile customers as soon as possible.

Update: Sprint has also delayed its Samsung Galaxy S4 launch, the company told The Verge in an email statement. The S4 will still launch online and via telesales on April 27th, but retail availability will come at an unspecified date.

Sprint is excited to launch the new Samsung Galaxy 4. We had planned to launch this next generation of the award-winning Samsung Galaxy line-up on Saturday, April 27. Unfortunately, due to unexpected inventory challenges from Samsung, we will be slightly delayed with our full product launch. Sprint is one of Samsung’s largest partners and we are working closely with them to launch in all Sprint channels as soon as possible. We expect to make Galaxy S4 available at www.sprint.com and Telesales (1-800-SPRINT1) as planned on Saturday with Sprint retail stores and other channels receiving devices as inventory becomes available.

Update: A Samsung spokesperson has provided a statement to The Verge, citing "overwhelming demand" for the Galaxy S4. Samsung expects initial supply to be limited, but says "We expect to fulfill inventory to meet demands in the coming weeks."