Corporation Tax Returns (CT600) — Accurate, On Time & Explained
From computations to filing — we explain results, claim allowances and keep you compliant.
Our Corporation tax pipeline
Records
Trial balance & adjustments reviewed.
Computation
Tax adjustments & capital allowances.
CT600 e‑file
iXBRL accounts & comps attached.
Payment & advice
Payment guidance and planning pointers.
What’s included in our CT service
- Tax computations from your final TB, with clear schedules
- Capital allowances (AIA, main/special-rate pools)
- Loss relief options assessed (carry back/forward, group relief)
- CT600 prepared and filed online with iXBRL attachments
- Payment references, deadline reminders and debrief meeting
Clear CT600 pack
Computation, return, and payment summary.
Tax payment
Usually 9 months + 1 day after period end.
CT600 filing
12 months after period end.
Large companies
Quarterly instalments may apply.
Common deductions & reliefs we check
Capital allowances
Pools, AIA and integral features.
Provisions & accruals
Tax adjustments and timing.
Interest & group relief
Restrictions and claims.
Loss relief
Carry back/forward and groups.
Late filing penalties — CT600
| Delay | Penalty |
|---|---|
| 1 day late | £100 |
| 3 months late | + £100 |
| 6 months late | HMRC may estimate the bill and add 10% of unpaid tax |
| 12 months late | + another 10% of unpaid tax |
Interest & surcharges
Late payment attracts interest. Large companies on quarterly instalments face different interest mechanics — we’ll confirm what applies to you.