Edit>preferences has a setting that will remember the last transaction.

You can also edit your vendor and set it to a preferred acct.

Resolution for 'account category issue: 'How do I turn on auto fill for expense accounts when I write bills? So when I pull up a vendor it fills in the account category every time?' available: Yes.

The account category issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the account category issue yourself by looking for a resolution described in the article. If it is a complex account category issue or you are unable to solve the issue, you may contact us by clicking here or by using other account category support options.

For more information about resolving issues related to account category in Quickbooks/QBO or to get support for the issue 'How do I turn on auto fill for expense accounts when I write bills? So when I pull up a vendor it fills in the account category every time?', click the link below: