In SpaceX's first quarterly report since going public, one buyer identified only as "Customer B" contributed 34.5% of the company's third-quarter revenue, all of it booked under a division called Super Intelligence. Bloomberg, citing people familiar with the matter, says the customer is Anthropic. Neither SpaceX nor Anthropic has confirmed this, and Anthropic declined to comment.
On the report's figures, SpaceX's third-quarter revenue was roughly $14.6 billion. At 34.5%, a rough calculation puts Customer B's payments for the quarter at about $5 billion, or around $1.7 billion a month.
One division, one dominant customer
Super Intelligence is the renamed version of SpaceX's former AI business unit, and it mainly sells computing capacity. It brought in $7.6 billion in the third quarter, up about 830% year on year. If all of Customer B's $5 billion landed in this division, roughly two-thirds of the unit's revenue would come from a single company. That is an estimate built from public numbers; the report does not break down customers within the division.
The report also mentions a "Customer A", which made up 16.6% of third-quarter revenue and 17.3% of the first nine months, with business spanning all three of SpaceX's divisions. Bloomberg's reporting links it to a customer connected to the US government; SpaceX has not named it either. Customer B's share over the first nine months was 24.2%, so its single-quarter figure stands well above that average, which suggests its payments ramped up sharply in the second half of the year.
The contract ceiling and the exit clause
Anthropic's own listing documents are more specific. It has agreed to pay SpaceX up to $120.5 billion for AI computing capacity through 2029, with the capacity located in a data center in Memphis, Tennessee. On the disclosed terms, once all the contracted capacity is delivered, the monthly payment would be about $3.1 billion.
The contracts can be cancelled on 90 days' notice starting in early 2027. For SpaceX, that means more than a third of its revenue rests on a contract the buyer can walk away from at any time. For Anthropic, it is another large source of compute alongside Google and Amazon, and the exit clause gives it leverage in negotiations.
A rough look at the ramp
The current rate is about $1.7 billion a month, against about $3.1 billion at full capacity, a gap of nearly double. As a back-of-the-envelope case, if payments ran at the full-capacity pace from the fourth quarter on, Customer B's quarterly payments would approach $9.3 billion, more than the entire third-quarter revenue of SpaceX's Super Intelligence division. That assumes the Memphis capacity is delivered on schedule, and neither company has published a delivery timetable.
The comparison with a year ago is starker. In the third quarter of 2025, Customer B made up less than 10% of SpaceX's revenue, below the threshold for separate disclosure. In one year it has gone from invisible in the filings to the largest customer.
Elon Musk has previously said SpaceX has locked in about $40 billion of GPU debt financing, tied to hardware arriving between now and the first half of 2027. The report does not say who will end up renting that hardware. On customer concentration, SpaceX lists the numbers in the report but offers no separate explanation of how it plans to deal with the risk.
Sources: SpaceX Q3 quarterly report (used to verify Customer B's 34.5% share, Customer A's 16.6% share and Super Intelligence division revenue), Bloomberg, CocoLoop, Anthropic's listing documents (used to verify the $120.5 billion ceiling and the 90-day cancellation clause), Cailian Press.