Articles and verbs in error codes. What and when to use?

Before we get to the question, I'm a beginner at UX writing and English is not my native language, so I apologize in advance for the wording.

I need to write texts for error codes, for example:


  1.  No response from (the) bank.

Try the following:

  • Use another card.

  • Try again later.


  1. Transaction (was) rejected by the bank.

Seems like you (have) entered (the) wrong CVV code.


And I'm wondering if a should use articles and verbs here. Thanks for help!