Authorise BrightBooks with HMRC, generate and finalise your VAT return on General Ledger → MTD VAT Returns, check the figures, then submit.

Connect BrightBooks to HMRC

1. Open the business and go to Settings → Change HMRC Credentials.
2. On the Information Message, select OK, then Continue on HMRC’s page.
3. Sign in with the HMRC sign-in for this VAT number (agents: your agent services account) and select Grant authority.

Generate and finalise the return

1. Go to General Ledger → MTD VAT Returns.
2. Open the drop-down for the period and select Generate VAT Return.
3. Select Include these transactions on this VAT Return, then Proceed.
4. Check the figures. Select Finalise, then Save.

Submit the return

1. Open the drop-down for the period and select Submit VAT Return.
2. Choose I am submitting my own VAT Return, or I am acting as an Agent for this business.
3. Tick the declaration and select Submit. The status shows Submitted.

Bring in older VAT periods

1. If a period you need isn’t listed, use Sync Historical MTD VAT Obligations and choose a start date. BrightBooks brings in up to a year of periods from HMRC.
2. Repeat with a later start date until every period you need is listed.

Known errors and how to fix them

Find the message you’re seeing:

• BrightBooks doesn’t ask for your HMRC sign-in, or there’s no Submit option
• “The client and/or agent is not authorised” or “invalid code”
• A VAT period you need isn’t listed
• “You can’t create the return until the previous one is closed”
• Your VAT return doesn’t match your ledger
• HMRC already has a return for this period (DUPLICATE_SUBMISSION)
• The VAT period hasn’t ended (TAX_PERIOD_NOT_ENDED)

BrightBooks doesn’t ask for your HMRC sign-in, or there’s no Submit option

What you’ll see

• You aren’t asked to sign in to HMRC, or Submit VAT Return isn’t available.

Why it happens

Your HMRC authority for MTD VAT has expired (it lasts 18 months), or your user doesn’t have permission to send VAT returns.

How to fix it

1. Go to Settings → Change HMRC Credentials and sign in again.
2. Check you have the Send VAT Return permission: Settings → GENERAL SETUP → Users → Permissions.

“The client and/or agent is not authorised” or “invalid code”

What you’ll see

• One of these messages when you connect or submit.

Why it happens

HMRC doesn’t link the sign-in you used to this VAT number. The business may not be signed up for MTD for VAT, or the client hasn’t authorised you as their agent. New agent clients can take 24 hours to appear on HMRC’s client list.

How to fix it

1. Check the VAT number is right for the business.
2. Agents: check the client’s authorisation in your agent services account.
3. Agents: set the MTD agent details from the MTD VAT Returns screen.
4. Go to Settings → Change HMRC Credentials and sign in with the right HMRC sign-in.

Still not working? Contact us if: you’ve reconnected and the message continues.

A VAT period you need isn’t listed

What you’ll see

• An older period, or a period HMRC has told you about, doesn’t appear on MTD VAT Returns.

Why it happens

BrightBooks shows the periods HMRC returns. Older periods aren’t brought in automatically.

How to fix it

1. Use Sync Historical MTD VAT Obligations with a start date before the missing period.
2. If nothing comes through, go to Settings → Change HMRC Credentials, sign in again, and sync again.
3. If the period still doesn’t appear, HMRC isn’t making it available to software for your VAT number. Check with HMRC how they want it filed – we can’t add periods manually.

“You can’t create the return until the previous one is closed”

What you’ll see

• This message although the earlier return looks closed.

Why it happens

An earlier VAT return – or an MTD for Income Tax return in the same business – is still open.

How to fix it

1. Check General Ledger → MTD VAT Returns for an earlier return that isn’t submitted.
2. Check General Ledger → MTD ITSA for an open return.
3. Finish or submit it, then create the new return.

Still not working? Contact us if: every earlier return is closed and the message continues.

Your VAT return doesn’t match your ledger

What you’ll see

• The return’s figures differ from your reports or VAT control account.

Why it happens

The return only includes transactions dated in the VAT period, on the business’s VAT basis, with VAT codes that feed the return. Transactions using the OSS VAT code are never included.

How to fix it

1. Don’t submit until the figures are right – you can’t amend a submitted return in BrightBooks.
2. Run Reports → General Ledger → VAT Return for the same period and compare.
3. Check the VAT basis (cash or invoice) on Settings → VAT.
4. Check transaction dates and VAT codes, for example items coded at 20% that should be 0%.
5. If the return is generated but not submitted, select Clear VAT Return from the drop-down, correct the transactions and generate the return again.

Still not working? Contact us if: your Northern Ireland address shows as Ireland, or box 5 shows the wrong sign for a refund – these are known issues.

HMRC already has a return for this period (DUPLICATE_SUBMISSION)

What you’ll see

• An error saying a return has already been submitted for the period.

Why it happens

HMRC already holds a return for this period.

How to fix it

1. Don’t submit again. Check the return on General Ledger → MTD VAT Returns or in your HMRC VAT account.
2. To correct a submitted return, follow HMRC’s VAT Notice 700/45 or ask your accountant.

The VAT period hasn’t ended (TAX_PERIOD_NOT_ENDED)

What you’ll see

• An error saying the period hasn’t ended.

Why it happens

HMRC only accepts a return once the VAT period has finished.

How to fix it

1. Wait until the day after the period end date, then submit.

Still need help?

Contact our support team. Send us the business name, the VAT period and a screenshot. Never delete a submitted or late VAT return to re-run it – contact us first.