Building a US Credit Score when new to the US

Hi,

I understand that there may be 3 firms that maintain your US credit history (Equifax, Trans Union and Experian). My question is about high quickly one can build a credit score in the US?

I have been living and working full time in the US for nearly 4 months and back in November purchased a new vehicle through Lexus Financial Services). My regular monthly payments on the vehicle start in January and the Lexus business office tells me that "they" will start reporting to the credit agencies after a few months. (He may have been guessing).

Now that my credit score = "No Score", what can expect as a reasonable time before a credit score might equal something like 620 to 750. Internet research tells me that 750 is the US average.

Ultimately we want to obtain a mortgage at an acceptable lending rate.
Thanks,

Credit score itself will not impact your mortgage rate.