UK VAT Making Tax Digital (MTD) Returns

What this is for

Odoo Community has no UK VAT return — l10n_uk_reports is Enterprise. This builds the nine boxes from the ledger and prepares the submission.

The box mapping

Accounting ▸ Configuration ▸ VAT Box Mapping

Every chart of accounts names its taxes differently, and a return built on guessed names is wrong in a way nobody notices until HMRC does. Each box says explicitly which taxes feed it, and whether it reports the VAT (boxes 1, 2, 4) or the net amount it was charged on (boxes 6 to 9).

Boxes 3 and 5 are never mapped: they are arithmetic on the others.

A box with nothing mapped reports zero and says so on the return, and the submission is refused until it is dealt with. Quietly filing a zero is how a missing mapping is discovered through an assessment.

Dealing with it can mean either thing. Most companies never make an EU acquisition, so boxes 2, 8 and 9 are nil for them for ever — tick Nil on purpose on those rows and the return stops treating them as unfinished work. A box cannot be both mapped and nil on purpose; that would be a contradiction about what the figure means.

The company has to keep its books in sterling

The nine boxes are read off the ledger in the company currency and sent to HMRC as bare numbers. The API carries no currency field, so a company keeping its books in euro would file euro totals under a pound heading and hear about it at the assessment. Submission is refused outside GBP, and the return says so on screen before anyone reaches the declaration.

A group that trades in both places handles this the way it already does: the British entity is its own company with its own GBP ledger, and the return is prepared there.

Obligations

HMRC issues the periods, and they are not always calendar quarters. Record each one with the period key HMRC gave it — a submission has to quote it back, and it is what ties a return to the obligation it satisfies.

Preparing a return

Pick the obligation, press Compute, and the boxes are filled from posted entries in the period. Amounts are reported positive on both sides, as the form expects.

Before it can be submitted:

• the declaration must be ticked — HMRC requires the submitter to confirm the figures are correct and complete, and the API rejects a submission without it;

• every box must be mapped, or explicitly confirmed as empty.

Submitting

This module does not carry HMRC credentials for you. Production access needs a registered application and an OAuth grant belonging to the company that files, not to a software vendor — so the honest shape is:

• the payload and the fraud-prevention headers are assembled and validated here, and nothing in the headers is invented (HMRC rejects fabricated values, and several can only come from the browser a human is sitting at — those are passed in by the caller);

• _bf_send is one small method to override with your own client;

• a submission accepted through another channel can be recorded against the obligation with its receipt.

Known limits

• Not tested against the live HMRC API. Everything up to the HTTP call is covered by tests; what happens inside that call cannot be verified without an HMRC developer account and a company's own grant.

• Obligations are entered or imported, not fetched — fetching them needs the same credentials.

• One VAT registration per company.