The short answer
You record losses and loss claims in your MTD software after the tax year ends on 5 April. In SimpleTaxFlow, open Losses and claims from the year-end steps, choose the business, enter the amounts and choose Save with HMRC. Carry back is available from the 2026 to 2027 tax year. The tax saved by carrying a loss back is not sent to HMRC yet. That part is not supported in SimpleTaxFlow today.
Loss claims in brief
A loss happens when your allowable expenses are more than your income for the year. HMRC lets you use it in different ways.
- Carry forward: use the loss against future profits of the same business
- Set against other income: use a trading loss against your other income in the same year
- Carry back: use a trading loss against income from an earlier year
1. Wait until the tax year has ended
From the 2026 to 2027 tax year, HMRC does not accept loss claims until the year ends on 5 April. Send your fourth quarterly update and make any year-end adjustments first.
Make year-end adjustments2. Open Losses and claims
Open Tax and choose Open year-end steps. Under Allowances, adjustments and losses, choose Losses and claims. You can also choose More, then Losses under Your tax tools.
Open Tax3. Choose the business and enter amounts
Choose the Business. Enter Brought-forward losses from earlier years. Use Carry forward this year’s losses or Carry forward unused earlier losses for losses you will use against future profits. Self-employment also shows Set against other income this year, Carry back against earlier income, Early-year loss carry-back and Terminal loss carry-back.
Open Tax4. Choose the order and save
If you set a loss against this year’s income and also carry one back, answer Which claim should HMRC apply first? Then choose Save with HMRC. You see Losses and claims saved with HMRC.
Open Tax5. Plan for the tax saved by a carry back
A carry back claim tells HMRC to use the loss against an earlier year. The tax saved in that earlier year is a separate figure. SimpleTaxFlow does not send it to HMRC yet. If you carry a loss back, ask an accountant or HMRC how to claim it.
Read HMRC’s loss guidance6. For 2025 to 2026, use the earlier layout
For the 2025 to 2026 tax year the panel is called Brought-forward losses & loss claims. Choose Add brought-forward loss, then Create loss. Choose Add loss claim, then Create claim. Carry back is not available for this year. With two or more claims of the same type, set the order under Loss claim priority and choose Save order.
Open Tax7. Recheck claims after a later change
If you send a business update or BSAS adjustment after a loss claim, the year-end steps show Review your loss claims again. Check HMRC’s figures and save the claim again before your tax return. Landlords can check figures already sent with Property period history under Your tax tools.
Submit your tax returnBefore you move on
- The tax year has ended
- Loss amounts match your earlier returns or your accountant’s records
- Claims were saved again after any later update
- You know how you will claim any tax saved by a carry back
- You kept a note of each loss, the year it arose and how you used it
- £30.00 + VAT a year or £3.50 + VAT a month. Bookkeeping is free. Pay when you send to HMRC.
Frequently asked questions
Does SimpleTaxFlow send the tax saved by a carry back?
Not yet. You can make the carry back claim. The tax saved in the earlier year is not sent to HMRC yet, so ask an accountant or HMRC how to claim it.
Can I claim a loss for foreign property?
Not yet. SimpleTaxFlow supports losses for self-employment and UK property.
Check the official rules
Tax rules can change and individual circumstances matter. Use HMRC’s current guidance to confirm the treatment that applies to you.
Put the guide into practice.
Open the relevant workspace and complete the next step with this guide available in another tab.
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