Two associated companies
- Latest version
- Version 1.2.0 Beta
- Last updated
- 10 November 2026
- API type
- REST
- Sandbox base URL
- Provided with sandbox access
- Production base URL
https://www.simplecompanytax.co.uk/api/v1
Developer documentation
An associated-companies guide request with two entered.
Company route · 1 CT600 return
Read the related filing guide.
Complete request
{
"form": {
"dormant_trading_history": "unanswered",
"disposal_calculations": "",
"disposal_calculations_second_return": "",
"company_name": "Hornbeam Example Ltd",
"registration_number": "00000001",
"utr": "0000000000",
"registered_office": "24 Fictional Lane, London, EC1A 1BB",
"period_start": "2025-04-01",
"period_end": "2026-03-31",
"no_prior_year": true,
"property_management_company": false,
"provisional_figures": false,
"provisional_figures_explanation": "",
"earlier_period_claim": false,
"earlier_period_claim_second_return": false,
"sme_transfer_pricing_exemption": false,
"sme_transfer_pricing_exemption_second_return": false,
"trade_ceased": false,
"close_investment_holding_company": false,
"close_investment_holding_company_different": false,
"no_trade_in_return": false,
"post_cessation_receipts": "",
"post_cessation_deduction": "",
"first_return_end": null,
"tax_coverage_start": "",
"tax_coverage_end": "",
"director_loan_waivers": [],
"remaining_ct600": false,
"hmrc_first_return_filed": false,
"hmrc_second_return_filed": false,
"external_original_filed": false,
"tcc_prior_return_accounts": false,
"tcc_hmrc_dates": false,
"tcc_no_earlier_activity": false,
"tcc_no_earlier_activity_wording": 0,
"filing_target": "hmrc",
"director_forename": "",
"director_surname": "",
"is_dormant": false,
"special_ct_regime": "no",
"associated_companies": "2",
"associated_companies_second": "",
"associated_companies_first_fy": "",
"associated_companies_second_fy": "",
"associated_companies_first_fy_second": "",
"associated_companies_second_fy_second": "",
"group_dividends_received": "",
"quarterly_instalments_status": "",
"quarterly_instalments_previous_count": "",
"quarterly_instalments_group_625": "",
"quarterly_instalments_status_second": "",
"quarterly_instalments_previous_count_second": "",
"quarterly_instalments_group_625_second": "",
"current_assets": "130650",
"cash_at_bank": "",
"share_capital": "100000",
"intangible_assets": "",
"investments": "",
"tangible_assets": "0",
"debtors": "",
"other_current_assets": "",
"creditors_within_year": "0",
"creditors_after_year": "0",
"retained_earnings": "30650",
"called_up_share_capital_not_paid": "",
"provisions_for_liabilities": "",
"prepayments_accrued_income": "",
"accruals_deferred_income": "",
"corporation_tax_recoverable": "",
"corporation_tax_recoverable_confirmed": "",
"num_employees": "1",
"turnover": "100000",
"other_trading_income": "0",
"cost_of_sales": "0",
"admin_expenses": "20000",
"staff_costs": "40000",
"depreciation": "0",
"balancing_charges_special_rate": "",
"capital_allowances_structures_and_buildings": "",
"capital_allowances_sba_qualifying_expenditure": "",
"capital_allowances_sba_first_claim": "",
"capital_allowances_sba_full_period_use": "",
"capital_allowances_sba_special_tax_site": "",
"capital_allowances_all_trade": "",
"capital_allowances_property_use": "",
"capital_allowances_aia": "",
"capital_allowances_aia_special_rate_part": "",
"capital_allowances_main_pool_wda": "",
"balancing_allowance_main_pool": "",
"balancing_allowance_special_rate": "",
"capital_allowances_special_rate_wda": "",
"capital_allowances_main_pool_additions": "",
"capital_allowances_special_rate_additions": "",
"capital_allowances_special_rate_additions_cars": "",
"capital_allowances_zero_emission_cars": "",
"balancing_charges_main_pool": "",
"company_business_type": "trading",
"interest_received": "0",
"interest_paid": "",
"trade_interest_paid": "",
"non_trading_exchange_losses": "",
"non_trading_exchange_gains": "",
"dividends_received": "",
"dividends_paid": "",
"trading_loss_carried_back": "",
"trading_loss_carried_back_second_return": "",
"trading_losses_brought_forward": "",
"trading_losses_same_trade_only": "",
"trading_losses_total_profits_claim": "",
"trading_losses_total_profits_claim_second_return": "",
"management_expenses": "",
"management_expenses_property_share": "",
"management_expenses_brought_forward": "",
"management_expenses_brought_forward_claim": "",
"management_expenses_brought_forward_claim_second_return": "",
"investment_business_treatment_answer": "",
"non_trade_deficits_brought_forward": "",
"non_trade_deficits_brought_forward_claim": "",
"non_trade_deficits_brought_forward_claim_second_return": "",
"deductions_allowance": "",
"deductions_allowance_second_return": "",
"intangible_amortisation_cir": "",
"intangible_asset_event": "",
"intangible_asset_event_returns": "",
"intangible_disposal_book_gain": "",
"intangible_disposal_book_loss": "",
"trade_intangible_realisation_credit": "",
"trade_intangible_realisation_debit": "",
"property_intangible_realisation_credit": "",
"property_intangible_realisation_debit": "",
"non_trading_intangible_realisation_credit": "",
"non_trading_intangible_realisation_debit": "",
"non_trading_intangible_loss_brought_forward": "",
"non_trading_intangible_loss_current_claim": "",
"non_trading_intangible_loss_current_claim_second_return": "",
"non_trading_intangible_loss_brought_forward_claim": "",
"non_trading_intangible_loss_brought_forward_claim_second_return": "",
"ceased_investment_business": "",
"ceased_investment_business_second_return": "",
"disallowable_expenses": "",
"pre_trading_expenditure_deduction": "",
"other_income_not_taxable": "",
"other_income_not_taxable_description": "",
"qualifying_donations": "",
"profit_on_disposal": "",
"other_income_not_elsewhere_included": "",
"other_income_not_elsewhere_included_description": "",
"property_income": "",
"gross_rental_income": "",
"property_entry_mode": "",
"property_cost_of_sales": "",
"property_staff_costs": "",
"property_other_charges": "",
"property_running_expenses": "",
"property_depreciation": "",
"property_disallowable_expenses": "",
"manual_property_tax_base": "",
"property_intangible_amortisation": "",
"property_losses_brought_forward": "",
"gross_chargeable_gains": "",
"capital_losses_arising": "",
"capital_losses_brought_forward": "",
"property_losses_brought_forward_pre_2020": ""
},
"declarant": {
"forename": "Robin",
"surname": "Finch",
"accounts_approval_date": "2026-10-01"
},
"dry_run": true
}