Many Tesla Model 3 owners may not get a tax credit offered on the purchase of electric vehicles (EV).

Tesla has announced that the first Model 3 will be delivered in December 2017. The company has also confirmed receiving reservations for more than 325,000 Model 3.

"A week ago, we started taking reservations for Model 3, and the excitement has been incredible. We've now received more than 325,000 reservations, which corresponds to about $14 billion in implied future sales, making this the single biggest one-week launch of any product ever. This interest has spread completely organically. Unlike other major product launches, we haven't advertised or paid for any endorsements," says Tesla.

Customers in the U.S. can get a federal tax credit of $7,500 for buying an EV. However, the limitations on the tax credit means that some customers may have to go empty-handed.

According to the Internal Revenue Code Section 30D, tax credits on EVs starts decreasing once a carmaker has sold 200,000 qualifying EVs in the U.S.

Tesla has not confirmed the total number of vehicles sold; however, in a letter to shareholders the company confirmed sales of about 42,000 Model S in 2014 and 2015. The automaker is also expected to deliver about 80,000 to 90,000 EVs this year. Analysts suggest that Tesla may sell 200,000 units mark by 2018, which is when the Model 3 is estimated to be delivered to most of the customers.

When Tesla has sold 200,000 EVs then the tax credit goes into a "phase out period," and the tax credits will be reduced to 50 percent in the following six months and then to 25 percent over the next six months.

However, some analysts have found a loop in the rule. The tax credit of $7,500 is not cut until the end of the quarter after which a company has delivered 200,000 cars. Tesla may intentionally hit the limit on the first day of the quarter and then deliver the remaining vehicles within the next six months, which will allow customers to save $7,500.

Elon Musk, the CEO and founder of Tesla, has not discussed the issue but his tweet hints that the company will take advantage of the loophole.

@RyanCasburn We always try to maximize customer happiness even if that means a revenue shortfall in a quarter. Loyalty begets loyalty.

— Elon Musk (@elonmusk) 3 April 2016

Getting a federal tax credit is one of the major incentives for customers to but an EV. The sales of Tesla Model 3 may get affected if customers do not get this incentive.