>> How can I handle salary expenses without an invoice or end date?

You will need to record your salary entry as a vendor bill with a payment because start/end dates are unavailable for journal entries.

>> How can I manage deferred revenues with different accounts?

You can't. It's more efficient to impact the P&L account from the invoice rather than splitting accounts in the balance sheet. Use the deferred revenue report to break down the details. This report can group entries to give you the same level of granularity as different balance sheet accounts.

>> How is VAT treated in deferrals?

VAT is handled immediately on invoices and doesn’t impact deferred revenue entries.

>> How does migration to Odoo 18 affect my existing deferred entries?

Since deferred revenue models have been removed, entries made before the migration remain unchanged, only the entries moving forward will use the new implementation.

>> Can I apply weights to my deferrals? Like 80% in the first month?

Yes, you just need to create multiple lines for the invoice, as there's no percentage field for deferrals.

>> How can I reconcile recurring payments like insurance with deferrals?

You will need to record an invoice, as deferrals don’t work with manual journal entries.