# Double/Triple Trailers — CDL endorsement prerequisites and testing sequence

For Double/Triple Trailers, test required is a knowledge test; allowed on a clp (learner's permit) is No — a CLP may carry only the Passenger, School bus and Tank vehicle endorsements, and this is not one of them, recorded from its source on 2026-08-19.

- **Endorsement:** Double/Triple Trailers _(verified: appears in the quote below)_
- **Test required:** a knowledge test _(verified: appears in the quote below)_
- **Allowed on a CLP (learner's permit):** No — a CLP may carry only the Passenger, School bus and Tank vehicle endorsements, and this is not one of them _(our reading, not quoted from the source)_

## What the source says

> The only endorsements allowed on a CLP are the following: ( i ) Passenger (P); ( ii ) School bus (S); and ( iii ) Tank vehicle (N). ( 3 ) The State must use the codes listed in <https://www.ecfr.gov/current/title-49/section-383.153> § 383.153 when placing endorsements on a CLP or CDL. ( b ) Endorsement descriptions. An operator must obtain State-issued endorsements to his/her CDL to operate commercial motor vehicles which are: ( 1 ) Double/triple trailers; ( 2 ) Passenger vehicles; ( 3 ) Tank vehicles; ( 4 ) Used to transport hazardous materials as defined in <https://www.ecfr.gov/current/title-49/section-383.5> § 383.5 ; or ( 5 ) School buses. ( c ) Endorsement testing requirements. The following tests are required for the endorsements contained in <https://www.ecfr.gov/current/title-49/section-383.93#p-383.93(b)> paragraph (b) of this section: ( 1 ) Double/Triple Trailers —a knowledge test;

## Source

- https://www.ecfr.gov/current/title-49/section-383.93

Last verified: 2026-08-19. Review by: 2027-08-19.
Part of [CDL endorsement prerequisites and testing sequence](https://referencesource.org/cdl-endorsement-prerequisites/).