Question 1

Where is area code 303?

Accepted Answer

Area code 303 covers Denver and nearby cities including Aurora, Lakewood, Thornton in Colorado, in the Mountain Time.

Question 2

What cities use area code 303?

Accepted Answer

Area code 303 serves Denver, Aurora, Lakewood, Thornton, Arvada, and 19 other communities in Colorado.

Question 3

What time zone is area code 303 in?

Accepted Answer

Area code 303 is in the Mountain Time (America/Denver).

Question 4

How do you dial a 303 number?

Accepted Answer

Dial all 10 digits: 303 followed by the 7-digit local number. From outside the United States, dial +1 303 and the local number.

Question 5

Is a call from area code 303 a scam?

Accepted Answer

A 303 number is geographically tied to Colorado, but caller ID can be spoofed, so the displayed area code does not prove where a caller really is. If you did not expect the call, do not share personal information and consider looking the number up.

Question 6

Is 303 a country code?

Accepted Answer

No. 303 is a US area code (a domestic 3-digit code), not a country code. The country (calling) code for the United States is +1. So a full 303 number written for international dialing looks like +1 303 followed by the 7-digit local number.

Area Code 303

Cities in area code 303

Area codes by city

Carriers in area code 303

Other Colorado area codes

Nearby area codes