If you can see a transaction under a different nominal code to that that the analysis code uses, it is likely that when the transaction was posted to the account, the analysis code used was set up to post to the nominal code that you can see the transaction under. The analysis code will then have been updated, but when this happens, any transactions that are already posted do not get updated when this change is made.
You can correct this, by following the below steps:
Go to Creditors
Select Enquiries
Then Purchase Transactions to load the required transaction
On the detail line, click the pop over button and then click Edit Transaction Details
Click on the magnifying glass next to the Analysis Code box and reselect the analysis code again.
Click Save
By reselecting the analysis code and saving the transaction, it will prompt the system to update the nominal codes accordingly.