Right way to ammend Invoices

Proper accounting procedure

[aspdaddy]

This has bugged me for a while, say you send a client an invoice and then later on agree to reduce the amount do you 1) re-invoice the new amount on the same Id, 2)send a credit note for the difference , 3) cancel/void and re-invoice on new ID?

All work , 1&2 are easier, whats the correct way of doing it from an accounting audit perspective?

Thanks

[snorkel100]

I usually like to change the original invoice with notes reflecting the changes.

The only reason I do this is so they dont get an extra 30 days to pay from the new date of invoice.

I also have an aversion to extra paperwork and doing credits and rebills makes my eyes glaze over.