The conditions for upgrading from a B2 to a B1 driver's license (B1 cannot be obtained directly but only through an upgrade) are: you must have held the B2 license for at least three years, have no record of accumulating 12 penalty points in the last three consecutive scoring cycles before the application, and be between 21 and 50 years old. If these conditions are met, you can apply for a B1 medium-sized passenger vehicle license at the issuing authority. Documents required for upgrading from a B2 to a B1 driver's license: "Motor Vehicle Driver's License Application Form"; Original and photocopy of identity proof; "Motor Vehicle Driver's Physical Condition Certificate" issued by a county-level or above hospital or a military medical institution at or above the regiment level; Eight 1-inch color headshots with a white background; For upgrade applications, the original motor vehicle driver's license must also be submitted; For applications submitted by driving school students, the training record issued by the school must also be submitted. Differences between B1 and B2 driver's licenses: Different permitted vehicle types; Different application requirements; Both B1 and B2 licenses must be applied for at the local vehicle management office in the applicant's registered residence. However, B2 can be obtained directly, while B1 requires holding another driver's license first and then applying for an upgrade. Permitted vehicle types for B1 license: medium-sized passenger vehicles and C1, M (M refers to wheeled self-propelled machinery). This includes urban buses with 10 to 19 passengers. Permitted vehicle types for B2 license: large trucks and C1, M. B2 license holders can drive heavy, medium, and large specialized operation vehicles, as well as small vehicles under C1 and M categories. According to the "Motor Vehicle Driver's License Business Work Standards" issued by the public security department, motor vehicle driver's licenses are classified into 15 levels: A1, A2, A3, B1, B2, C1, C2, C3, C4, D, E, F, M, N, P. The permitted vehicle types for each license level are as follows: A1 license: large passenger vehicles. A2 license: tractor, heavy and medium full-trailer and semi-trailer vehicle combinations. A3 license: urban buses with 10 or more passengers. B1 license: heavy passenger vehicles. B2 license: heavy and medium trucks, etc. C1 license: small and mini passenger vehicles, etc. C2 license: small and mini automatic transmission passenger vehicles, etc. C3 license: low-speed trucks (formerly four-wheel agricultural transport vehicles). C4 license: three-wheeled vehicles (formerly three-wheeled agricultural transport vehicles). D license: three-wheeled motorcycles with an engine displacement exceeding 50ml. E license: two-wheeled motorcycles with an engine displacement exceeding 50ml. F license: motorcycles with an engine displacement of 50ml or less. M license: wheeled self-propelled machinery. N license: trolleybuses. P license: trams.
