CT600 from Spreadsheets: Excel and Google Sheets
Many small company directors track their finances in spreadsheets. Whether you use Excel, Google Sheets, or another tool, this guide shows you how to prepare your figures for CT600 filing.
Is Spreadsheet Bookkeeping Acceptable?
Yes. HMRC doesn't require specific accounting software. Your records must be:
- Accurate and complete
- Able to support your tax return figures
- Kept for at least 6 years
- Available for inspection if requested
Essential Spreadsheet Records
Your spreadsheet accounting should track:
Income Records
- Date of each sale
- Customer name or description
- Invoice number (if applicable)
- Amount (net of VAT if registered)
- Payment status
Expense Records
- Date of purchase
- Supplier name
- Description of expense
- Category (e.g., office costs, travel)
- Amount paid
- Receipt reference
Bank Reconciliation
- Opening and closing balances
- All transactions matched to records
- Explanation of any differences
Calculating Your CT600 Figures
From your spreadsheets, you need to extract:
Box 145 - Turnover
Total all income for the accounting period:
``` =SUMIF(IncomeSheet, DateColumn, ">=start_date", "<=end_date", AmountColumn) ```
Or simply total your income column for the relevant dates.
Trading Profit
Calculate:
Total Income - Total Allowable Expenses = Trading Profit
Allowable Expenses
Sum your expense categories:
- Cost of goods sold
- Staff costs
- Premises costs (rent, utilities)
- Office costs
- Professional fees
- Travel expenses
- Marketing costs
- Other business expenses
What Spreadsheets Can't Do
While spreadsheets track figures, they don't:
- File CT600 electronically to HMRC
- Generate iXBRL accounts for Companies House
- Calculate corporation tax automatically
- Apply capital allowances rules
Preparing Your Year-End Summary
Create a summary sheet with:
| Item | Amount |
|---|---|
| Total Sales/Turnover | £XX,XXX |
| Cost of Sales | £X,XXX |
| Gross Profit | £XX,XXX |
| Operating Expenses | £X,XXX |
| Net Profit Before Tax | £XX,XXX |
Common Spreadsheet Mistakes
Double-Counting
Watch for transactions appearing in multiple sheets or categories.
Missing Transactions
Bank statements may show items not in your records. Reconcile monthly.
Incorrect Categorisation
Personal expenses mixed with business, or expenses in wrong categories.
VAT Errors
If VAT registered, ensure you're recording net amounts consistently.
From Spreadsheet to TinyTax
With your spreadsheet figures prepared:
- Gather totals - Income, expenses by category, profit
- Start CT600 - Begin your filing in TinyTax
- Enter figures - Input your turnover and profit
- Add adjustments - Capital allowances, disallowable expenses
- Review - TinyTax calculates your tax
- File - Submit to HMRC and Companies House
Fixed Assets and Capital Allowances
Track fixed assets separately:
| Asset | Purchase Date | Cost | Category |
|---|---|---|---|
| Laptop | 15/04/2024 | £800 | Equipment |
| Desk | 20/05/2024 | £200 | Furniture |
Should You Upgrade from Spreadsheets?
Consider proper accounting software if:
- Turnover exceeds £20,000-30,000
- You have many transactions monthly
- VAT registration is required
- Multiple people need access
- You want automatic bank feeds
Keeping Good Records
Regardless of format, maintain:
- Original receipts (paper or digital)
- Bank statements
- Sales invoices
- Purchase invoices
- Contracts and agreements
- Year-end summaries
Filing Your CT600
TinyTax accepts figures from any source, including spreadsheets:
- No trial balance import needed - just enter totals
- Clear prompts for each required figure
- Automatic tax calculation
- Built-in validation checks
- Direct HMRC and Companies House submission
Key Takeaways
- Spreadsheet bookkeeping is acceptable for CT600
- Track income, expenses, and bank reconciliation
- Create a year-end summary of key figures
- TinyTax accepts manual entry of your totals
- Consider upgrading software as your business grows