Dave's ESL Cafe's Student Discussion Forums

[app]

I have paid $5000 more than the amount I should pay.

[bud]

I think it's pretty typical for casual conversation.

Technically, though, I think you'd need to make the second verb phrase in the present perfect tense, the same as you did with the first: I have paid $5000 more than the amount I should have paid.

Then it would be grammatical and thus appropriate for formal purposes. That's only my opinion, though. I'm a native speaker, but not an expert in grammar.

Hope that helps.

[app]

Thanks. I also think what you said is right.