Deferred Tax Calculator — Month-End Journal

Computes the deferred tax asset (DTA) or liability (DTL) movement for the period and produces the double-entry journal entry. Enter figures from the last filed accounts and the current period NBV. Blue hints show exactly where to find each figure.

Reporting framework

FRS 102 s1A — deferred tax required on all timing differences (FRS 102 para 29).

Corporation tax & period

CT rate applying (%)

Where to find: CT600 box 430 (standard rate) or 435 (marginal). 25% main / 19% small profits / marginal if profits £50k–£250k.

Month-end date

Used in journal narration only

Opening deferred tax balance (last filed accounts)

DT balance per last filed accounts

Filed accounts: Balance sheet — Creditors: amounts falling due after more than one year (DTL) or Debtors (DTA). Note for deferred tax is usually note 12–15 depending on template. In Iris Elements: Tax > Deferred Tax.

Balance type

DTL = timing diff results in future tax payable. DTA = future deductible.

Prior year total NBV per accounts

Filed accounts: Fixed assets note — net book value at year end. All asset classes combined.

Prior year total tax WDV (from CT600)

CT600 / tax computation: Capital allowances workings — WDV carried forward (main pool box 90, special rate box 160, structures box 330 etc). Add all pools.

Current period assets one row per asset class or individual asset

Where to find current figures: NBV from your fixed asset register or Xero fixed assets module (Reports > Fixed Assets). Tax WDV: HMRC capital allowances pools updated to current date — note AIA, FYA and super-deduction assets may have nil WDV. Check if any asset disposed of in period.

Other timing differences

Accruals / provisions (not yet tax deductible)

Book charge precedes tax deduction → creates DTA

Xero: Balance sheet accruals / provisions line. CT600 tax computation — items added back.

Prepayments / deferred income (taxable before recognised)

Tax deduction precedes book charge → creates DTL

Xero: Prepayments on balance sheet. Any deferred income creditor treated as taxed on receipt.

Tax losses carried forward (unutilised)

Creates DTA — only if future profits probable

CT600: Box 780 (losses available for carry-forward) or prior year loss memorandum in Iris Elements.

Other timing differences (net)

Positive = creates DTL, negative = creates DTA