Turn on reimbursable expenses
gear>settings>company settings
expenses>bills & expenses

When you enter a bill, you will see a Billable check mark box, check that. The next time you invoice your customer, the system will ask if you would like to add the bill to the invoice.

Then use the deposit/retainer item you used to […]

Resolution for 'billed to customer issue: 'How to record expenses to be billed to customer' available: Yes.

The billed to customer 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 billed to customer issue yourself by looking for a resolution described in the article. If it is a complex billed to customer issue or you are unable to solve the issue, you may contact us by clicking here or by using other billed to customer support options.

For more information about resolving issues related to billed to customer in Quickbooks/QBO or to get support for the issue 'How to record expenses to be billed to customer', click the link below: