Losses: Brought Forward & Carried Forward
Use previous year losses to reduce corporation tax. Learn how brought forward losses work, where to enter them, and how they offset profits.
If your company made a loss in previous years, you can use those losses to reduce this year's tax bill. This guide explains how losses work in TinyTax.
What Are Brought Forward Losses?
When your company makes a loss, you can carry it forward to future years. These "brought forward losses" offset future profits, reducing your corporation tax.
Example:
- 2023-24: Company made a £20,000 loss
- 2024-25: Company made a £50,000 profit
- Brought forward loss: £20,000
- Taxable profit: £30,000 (£50,000 - £20,000)
Where to Enter Losses
In the Tax Computation section of the form, you'll see:
Enter the total losses from previous years that you want to use this year.
How Losses Reduce Your Tax
``` Trading profit before losses £50,000 Less: Losses brought forward -£20,000 ───────────────────────────────────────── Net trading profit (Box 165) £30,000 ```
Corporation tax is calculated on the reduced profit, saving you money.
``` Property income (Box 170) £50,000 Less: Losses brought forward -£20,000 ───────────────────────────────────────── Adjusted property income £30,000 ```
Corporation tax is calculated on the reduced income, saving you money.
Key Box Numbers for Losses
| CT600 Box | Description |
|---|---|
| Box 155 | Trading profit before losses |
| Box 160 | Losses brought forward used against trading profit |
| Box 165 | Net trading profit after losses |
| Box 780 | Current year loss (if making a loss this year) |
| CT600 Box | Description |
|---|---|
| Box 170 | Total property income |
| Box 190 | Property income before losses |
| Box 250 | Property losses brought forward |
| Box 800 | Current year property loss (if making a loss this year) |
First Year Companies
If this is your company's first accounting period, the losses field is hidden.
If you're seeing hidden loss fields but believe you should have losses, check that your accounting period dates are correct.
Partial Use of Losses
You don't have to use all your losses at once:
Example:
- Losses available: £100,000
- This year's profit: £30,000
- Losses used: £30,000 (reduces profit to zero)
- Remaining losses: £70,000 (carry forward to next year)
| Field | Amount |
|---|---|
| Losses brought forward entered | £100,000 |
| Losses applied this year | £30,000 |
| Losses to carry forward | £70,000 |
Current Year Losses
If your company is making a loss this year:
- Your profit figures will show a negative number
- TinyTax calculates the loss automatically
- You'll see the loss in Box 780 (trading loss)
- You'll see the loss in Box 800 (property loss)
- Use these losses in future profitable years
- Use current year losses against past profits (via TinyTax)
- Get a tax refund for losses (special rules apply - ask an accountant)
Loss Restrictions
You can only offset losses against profit
If your profit is £30,000, you can only use £30,000 of losses - not more. The rest carries forward.
Order of application
Trading losses are applied in this order:
- Trading losses first (Box 160 against Box 155)
- Then against other income like interest (Box 285)
Property loss restrictions
Property losses can only offset:
- Property income from the same or future years
- Some other income (with restrictions)
Group relief
If your company is part of a group, losses can sometimes be surrendered between companies. TinyTax doesn't handle group relief - speak to an accountant.
Where to Find Your Loss Figures
Check these sources for your brought forward loss amount:
- Last year's CT600 - Look at Box 780 (trading loss to carry forward)
- Your accountant's computations - Should show losses carried forward
- Previous TinyTax submission - Check the "Losses to carry forward" figure
- Last year's CT600 - Look at Box 800 (property loss to carry forward)
- Your accountant's computations - Should show losses carried forward
- Previous TinyTax submission - Check the "Losses to carry forward" figure
Extended Periods (>12 months)
For accounting periods longer than 12 months, TinyTax splits into two CT600s:
- Period 1: Uses your brought forward losses first
- Period 2: Uses any remaining losses, plus any losses generated in Period 1
Common Questions
"The losses field is hidden"
This happens when:
- It's your company's first accounting period
- You're filing as Dormant (no losses for dormant companies)
- The field hasn't loaded - try refreshing the page
"I entered losses but my tax didn't change"
Check that:
- You have profits to offset (losses can't make tax negative)
- The figure saved correctly (check it's still showing)
- The tax computation section updated
"How do I know what losses I have?"
"Can I claim losses from many years ago?"
Verification
After entering losses, check the Tax Computation shows:
- Losses brought forward: Your entered amount
- Losses applied: Amount used against this year's profit
- Losses remaining: What carries forward to next year
Loss-Making Company This Year?
If you're making a loss this year (profit is negative):
- Enter your P&L figures as normal (showing the loss)
- TinyTax calculates Box 780 (trading loss) automatically
- TinyTax calculates Box 800 (property loss) automatically
- The loss appears in "Losses to carry forward"
- Use it in future years when you're profitable
Still Have Questions?
Last updated: December 2025
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