How to claim intangible amortisation or impairment on a CT600
Short version. SimpleCompanyTax uses your prepared accounting charge and qualifying tax deduction. Include the charge once in Profit & loss, then enter one combined amortisation-or-impairment deduction in Tax adjustments. We use your figures without deciding whether the asset qualifies.
1. Enter the trading accounting charge
Open Financial data, then Profit & loss. Under Trading income and expenses, include the charge in Depreciation and amounts written off assets. This total can contain tangible depreciation as well as intangible amortisation and impairment. Do not also include the same charge in Other charges.
2. Enter your prepared tax deduction
In Tax adjustments, use Intangible amortisation or impairment deductible (Part 8 CTA 2009). Enter one combined qualifying accounts-based deduction. For example, £1,000 qualifying amortisation plus £2,000 qualifying impairment means a single entry of £3,000.
The field restores relief after the automatic depreciation add-back. Its amount must be included in the corresponding depreciation figure and cannot exceed the available total. This is the limit of this input, not a statement that every Part 8 deduction is calculated in this way.
Partial deduction example: your prepared accounts contain a £2,000 impairment and your tax working gives a £1,500 deduction. Include £2,000 in the accounting charge and enter £1,500 in the deduction field. The £500 difference stays added back for tax. These figures illustrate entry only, not an assumed tax percentage.
3. Keep the property share separate
For property activity, enter its accounting charge in Depreciation and amounts written off assets under Property income and expenses. Enter its prepared deduction in Property qualifying intangible amortisation or impairment, under Property tax treatment in Tax adjustments.
A company with both activities enters each share in its own fields. A property-only company uses the property fields. Do not duplicate a deduction in trading and property. Read the property income guide for the existing property tax-base override.
4. Check the review and computation
At Review, check the accounting charge, deduction and resulting profit or loss. The trading line is Less: intangible amortisation or impairment (Part 8). Property deductions appear in the property reconciliation. Generate a fresh draft and check the same amounts in the tax computation.
For a short period, enter prepared figures for that Corporation Tax period. If the filing produces two CT600s, the existing time-apportionment calculation divides this deduction. Check each return and computation. This field does not offer a separate transaction-based allocation.
5. Check the treatment before choosing the field
This field covers the supported accounts-based deduction, not fixed-rate relief or disposal and other realisation debits or credits. A write-off is not automatically an impairment or a fully deductible expense. Use the treatment in your prepared tax working. If it is a realisation, this field does not provide that filing treatment.
For intangibles the company held before 1 April 2002, check HMRC's Part 8 scope rules and exceptions. For goodwill or customer-related intangibles bought on or after 8 July 2015, check the restrictions for the acquisition date. Relief can be restricted or use a fixed rate which this field does not support.
Read when amortisation can be deductible and impairment of a franchise or software licence. HMRC explains the conditions in CIRD12755 and business-use allocation in CIRD13520.