ok thanks. but in my case, the Tax Rounding on the Nexus is at the transaction level and when i would like to overwrite the tax1amt of 1 centime, netsuite is recalculating and doesn't allow me to do the change. It's only when i'm trying to add or remove 1 centime that i have an issue. If i add 2 centimes, netsuite is OK. But I need to add or remove 1 centime. In your case, you are able to add or remove 1 centime ? And what's your Tax rounding level (on transaction or item line level ) ?