Question

Is the following sentence missing commas? If so where?: You will not be able to get in unless I accidentally left a door unlocked.

Answer 1

By AP style needs not.

Explanation:

This is a complex sentence and before dependent clause you need not any COMMA.

But by Cambridge or the British grammarians somewhere use a COMMA before dependent clause too. Like unless is a connecting word for the dependent clause.

Personally, I use AP style as it is a wide spread in the world.