Business adjustments (BSAS)

Business Adjustments is an advanced annual step that drives HMRC's Business Source Adjustable Summary (BSAS) for a single property or self-employment business and tax year. It triggers an HMRC calculation, then lets you submit accounting adjustments to the income and expense totals. These sit on top of the figures the app built from your records and do not change your underlying transactions.

What Business Adjustments is

Business Adjustments drives HMRC's BSAS (Business Source Adjustable Summary) flow for a single property or self-employment business and one tax year. It does two things:

1. It asks HMRC to calculate a summary for that source.
2. It lets you submit accounting adjustments to the income and expense totals before the year is finalised.

The adjustments sit on top of the figures the app has already built from your recorded transactions. They do not change your underlying transaction records: they are an accounting overlay sent to HMRC for that source and tax year.

This is an advanced annual step, and most people will not need to enter manual adjustments. It is also the engine behind the Confirm with HMRC button on Year-End Review: that button runs the same BSAS flow with no changes, simply to finalise a source. See Year-end and the Final Declaration.

Note: What an adjustment means for your tax is a tax matter. The app provides the fields; whether and how to use them is between you and HMRC or your accountant.

Before you start

1. Connect your HMRC account. The Business Adjustments item only appears in the Tax & MTD navigation once HMRC is connected, so this step is required. See Connect your HMRC account.
2. Record your income and expenses first. The figures HMRC calculates come from the transactions you have recorded, so add them by hand or via CSV import before you start.
3. Submit your quarterly updates first. Adjustments build on the year's figures, so the Start Adjustments button stays disabled until all four quarterly updates for the year are submitted. You will see a reminder if any are still outstanding. See Submit a quarterly update.

Note: Business Adjustments is available on both Free and MTD Lite, for property and self-employment alike. You just need a connected HMRC account.

Run the 4-step wizard

Business Adjustments is a four-step wizard: Review, Calculate, Adjust, Submit.

1. Open Business Adjustments from the Tax & MTD navigation, or go to /tax/adjustments.
2. Choose the business and tax year. Pick the business type (property or self-employment, depending on your income types). The tax year defaults to the previous tax year.
3. Review. Step through Review to see the source and year you are working on.
4. Calculate. Move to Calculate to trigger or retrieve the HMRC BSAS summary for that source. This asks HMRC to produce the figures you will adjust.
5. Adjust. On the Adjust step, enter adjustment values only for the income and expense fields you need to change. Leave the rest blank. Negative values are allowed where a downward adjustment is needed.
6. Submit. Confirm and Submit the adjustment to HMRC.

Tip: Use the Submissions back button to return to your submission history at any point.

Property: finance costs are excluded

For a property business, BSAS deliberately leaves out residential finance cost (mortgage interest). There is no field for it here, and you cannot adjust it on this page. Finance costs are handled through your quarterly updates instead, not through BSAS.

If you need to change a finance-cost figure, record the mortgage-interest transactions and let them flow into your cumulative quarterly updates. See Section 24 and finance costs.

How this fits with year-end

HMRC requires every business source to be finalised before your Final Declaration. Submitting your annual figures alone does not finalise a source, so HMRC may still report that a source needs final confirmation.

There are two ways to finalise:

• No changes needed: use Confirm with HMRC on the relevant Step 2 row in Year-end and the Final Declaration. That runs the same BSAS flow with zero adjustments.
• You have figures to change: open Business Adjustments and submit the real adjustments, which finalises the source the same way.

For property data that is annual-only (adjustments and allowances rather than period figures), use Property annual finalisation instead. That is a separate annual submission and is the home for those fields.

If something goes wrong

• Business Adjustments is not in the menu. The item is hidden until your HMRC account is connected. Connect HMRC, then it appears. See Connect your HMRC account.
• The page is empty or shows a "not enrolled" state. Your HMRC account is not yet signed up for Making Tax Digital for Income Tax, so HMRC returns no data. Complete the connection, confirm your MTD enrolment, then refresh. See Not signed up for MTD yet?.
• Year-end still says a source needs final confirmation (HMRC error C95005). The annual figures alone do not finalise the source. Click Confirm with HMRC on that source's Step 2 row, or enter your real adjustments here in Business Adjustments. See Year-end and the Final Declaration.
• You cannot find a mortgage-interest or finance-cost field for a property. This is by design: property BSAS excludes residential finance cost. Handle it through your quarterly updates instead.
• Self-employment is not in the business picker. The picker only lists the business types on your account. If self-employment is missing, your account does not include a self-employment business. Self-employment is available as your single income type on Free, or alongside property on MTD Lite.

For anything about what an adjustment means for your tax, or whether you need one, check with HMRC or your accountant, or see the MTD guide.

Frequently asked questions

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