Does it generate the CA3 return?
No. It gives the net bases and VAT by rate, collected and deductible, and the balance for the period, in the shape you carry over to the return. An option rounds displayed amounts to the currency unit as the CA3 or SIMPL forms do. Filing stays in your tax portal.
Which VAT regimes are supported?
Accrual (invoice date), cash (pro rata of payments received in the period) and mixed (goods on accrual, services on cash, the French common-law regime). Down-payment invoices are always taken on a cash basis. You can view the grid in another regime without changing the configuration.
Where do the add-back amounts come from?
From the general ledger when the Accounting module is populated, otherwise from supplier invoice lines through their accounting allocation. The screen always states the source used. Unit ceilings compare the unit price including tax, line by line.
Can I use it outside France?
Yes. Presets exist for France, Switzerland and Morocco (proportional scale by threshold, minimum contribution, input VAT deductible on payment). Legal rates, ceilings, brackets and account prefixes are editable, which matters outside the French chart of accounts.
Does the figure match the native Dolibarr VAT report?
Situation invoices are handled exactly like the native report so both agree. Drafts and abandoned invoices are excluded, credit notes are counted negatively. In cash regime, VAT is rounded per period, so a multi-instalment invoice can differ by one cent across periods.
Does it write anything into my accounting?
No. The module only reads invoices, payments and ledger entries. It stores only its tax brackets and ceilings in two tables, which are kept if you disable it.