How to file company tax in the UK
The end-to-end process for directors. Read →
GUIDES
Guides for UK company directors.
Plain-English explanations of the terms, deadlines, and decisions that come up when you run a UK limited company. No accountancy jargon. No upsells.
REFERENCE
Key reference guides.
Long-form references on the core mechanics of UK company tax filing.
What is a CT600?
The electronic corporation tax return, explained. Read →
What is a micro-entity?
Thresholds, filing rules, and when they change. Read →
Dormant company tax return
HMRC dormancy and the CT600 side. Read →
Can I file company tax myself?
Realistic guide to self-filing. Read →
File dormant accounts online
Companies House dormant accounts in one flow. Read →
How to amend a CT600
Correct a filed return: HMRC amendments and Companies House revised accounts, step by step. Read →
Audit exemption for micro-entity accounts
Why audit-exemption settings are applied automatically to supported accounts. Read →
Balancing charges: selling an asset you claimed capital allowances on
Sold an asset you claimed AIA on? Where to enter the balancing charge and profit on disposal. Read →
Selling a property or investment: chargeable gains on your CT600
Company sold a property or investment? How to compute the gain and file boxes 210-220 with us. Read →
CT600 filing errors, explained
Understand common HMRC rejection codes, and the checks that stop a bad return before it is sent. Read →
Disallowable expenses: entertaining, fines and your Corporation Tax
Entertaining and fines stay in your accounts but are added back for tax. Here is how to enter them. Read →
Dividends in your accounts
Where dividends paid and received appear in your annual accounts. Read →
Dividends received and your Corporation Tax rate
Dividends received are exempt from tax but can still change which Corporation Tax rate you pay. Read →
Companies that own property and shares: what we can file
Owns property and listed shares? How each part is taxed, and the FRS 105 rules that apply. Read →
Filing to HMRC, Companies House, or both
Choose both filing destinations or send only the outstanding filing. Read →
Final CT600 when your company has stopped trading
File the last Corporation Tax return and stop HMRC expecting another one. Read →
Setting up a Government Gateway account to file Corporation Tax
Create a Government Gateway ID, add Corporation Tax, and link your company UTR before you file. Read →
LLPs: what you file instead of a CT600
Why an LLP files an SA800 rather than a CT600, and why we cannot file for LLPs. Read →
Your first year: filing when your accounting period is over 12 months
Why a long first period needs two CT600s and how we handle the split. Read →
Loss carry-back claims and Corporation Tax refunds
Show an expected refund in your accounts and make the claim with HMRC. Read →
Paying your Corporation Tax after you file
When and how to pay HMRC using the correct accounting-period reference. Read →
PDF copies of your filing documents
View, print, and share PDF copies of everything that was filed, including next year’s carry-forward figures. Read →
Property income on your CT600: rent, expenses and property losses
File rent from UK property: the box 190 net figure, property losses, and what is out of scope. Read →
Which company types SimpleCompanyTax supports
We file for UK private limited companies that are micro-entities. See what is in and out of scope. Read →
Using trading losses to reduce your Corporation Tax
Use an earlier trading loss against this year’s trading profit. Read →
Know the rules. File with confidence.
From £10 per company, per year. CT600, iXBRL, and Companies House — one flow.