{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://spreadsheets.diyaccounting.co.uk/schema/diya-gl-book-v2.schema.json",
  "title": "DIY Accounting GL-aligned Book Configuration (v2)",
  "description": "Schema for book.toml after parsing. Field names adapted from XBRL Global Ledger Taxonomy Framework 2015 (gl-cor, gl-bus, gl-taf modules). Validates the output of @iarna/toml or similar TOML parsers. Reference: http://www.xbrl.org/int/gl/2015-03-25/gl-framework-REC-2015-03-25.html. v2 adds the tables a book needs to state opening balances, stock, debtors, creditors, the fixed asset register, hire purchase agreements, dividends, the register of members and registered charges.",
  "type": "object",
  "required": ["documentInfo", "entityInformation", "accounts"],
  "additionalProperties": false,
  "properties": {
    "documentInfo": {
      "type": "object",
      "description": "gl-cor:documentInfo — Metadata about this set of books",
      "required": ["entriesType", "periodCoveredStart", "periodCoveredEnd", "defaultCurrency"],
      "additionalProperties": false,
      "properties": {
        "entriesType": {
          "type": "string",
          "enum": [
            "journal",
            "entries",
            "account",
            "balance",
            "trial_balance",
            "assets",
            "tax_tables",
            "versioning",
            "master_file",
            "trade_documents",
            "profile_compliant",
            "other"
          ],
          "description": "gl-cor:entriesType — What kind of data this book contains. Enumeration from GL 2015 specification."
        },
        "language": {
          "type": "string",
          "pattern": "^[a-z]{2}$",
          "default": "en",
          "description": "gl-cor:language — ISO 639-1 language code"
        },
        "creationDate": {
          "type": "string",
          "format": "date",
          "description": "gl-cor:creationDate — When this book file was created (ISO 8601)"
        },
        "periodCoveredStart": {
          "type": "string",
          "format": "date",
          "description": "gl-cor:periodCoveredStart — First day of the accounting period (ISO 8601)"
        },
        "periodCoveredEnd": {
          "type": "string",
          "format": "date",
          "description": "gl-cor:periodCoveredEnd — Last day of the accounting period (ISO 8601)"
        },
        "defaultCurrency": {
          "type": "string",
          "pattern": "^[A-Z]{3}$",
          "default": "GBP",
          "description": "gl-cor:defaultCurrency — ISO 4217 currency code"
        },
        "entriesComment": {
          "type": "string",
          "description": "gl-cor:entriesComment — Free text note about this book"
        },
        "diya-gl:vatStaggerGroup": {
          "type": "integer",
          "enum": [1, 2, 3],
          "description": "diya-gl: extension — Which of HMRC's three VAT stagger groups this business's quarters fall on. Group 1 ends Mar/Jun/Sep/Dec, group 2 Apr/Jul/Oct/Jan, group 3 May/Aug/Nov/Feb."
        },
        "diya-gl:payrollYearStart": {
          "type": "string",
          "format": "date",
          "description": "diya-gl: extension — The first day of the payroll calendar the Payslips workbook builds, when it differs from periodCoveredStart."
        },
        "diya-gl:formatVersion": {
          "type": "string",
          "description": "diya-gl: extension — The diya-gl-books format name and version this file is written as, e.g. \"diya-gl-books/1\"."
        },
        "diya-gl:engineVersion": {
          "type": "string",
          "description": "diya-gl: extension — The npm package version and commit of the engine that wrote this file, e.g. \"1.0.0+3f2a1b9c4d7e\"."
        },
        "diya-gl:taxDataHash": {
          "type": "string",
          "description": "diya-gl: extension — A hash over every app/data/*.toml tax-year file, naming which rates this file's figures were calculated from."
        },
        "diya-gl:templateHash": {
          "type": "string",
          "description": "diya-gl: extension — A hash over this product's own Excel template files, naming which workbook this file reproduces."
        },
        "diya-gl:templateScorecard": {
          "type": "string",
          "description": "diya-gl: extension — The published reconciliation check counts for this product's template, e.g. \"132 passed, 0 warnings, 0 failed\"."
        },
        "diya-gl:reconciledCommit": {
          "type": "string",
          "description": "diya-gl: extension — The commit whose CI reconciliation run last passed for this product, the proof this file's figures rest on."
        }
      }
    },

    "entityInformation": {
      "type": "object",
      "description": "gl-cor:entityInformation + gl-bus:organizationInformation — Who this book belongs to",
      "required": ["organizationIdentifier"],
      "additionalProperties": false,
      "properties": {
        "organizationIdentifier": {
          "type": "string",
          "description": "gl-bus:organizationIdentifier — Trading name or legal entity name"
        },
        "organizationDescription": {
          "type": "string",
          "description": "gl-bus:organizationDescription — Nature of the business"
        },
        "organizationAddressLine": {
          "type": "string",
          "description": "gl-bus:organizationAddressLine — Registered or trading address, first line"
        },
        "organizationTown": {
          "type": "string",
          "description": "gl-bus:organizationTown — Registered or trading address town/city"
        },
        "organizationPostcode": {
          "type": "string",
          "description": "gl-bus:organizationPostcode — Registered or trading address postcode"
        },
        "organizationTelephone": {
          "type": "string",
          "description": "gl-bus:organizationTelephone — Contact telephone number"
        },
        "taxRegistrationNumber": {
          "type": "string",
          "description": "gl-taf:taxRegistrationNumber — HMRC Unique Taxpayer Reference (UTR)"
        },
        "taxAuthorityIdentifier": {
          "type": "string",
          "default": "HMRC",
          "description": "gl-taf:taxAuthorityIdentifier — Tax authority identifier"
        },
        "diya-gl:product": {
          "type": "string",
          "enum": ["BasicSoleTrader", "SelfEmployed", "TaxiDriver", "Company", "Payslip05", "Payslip10", "Payslip20"],
          "description": "diya-gl: extension — DIY Accounting product identifier. Determines which schema subset is active."
        },
        "diya-gl:vatRegistered": {
          "type": "boolean",
          "default": false,
          "description": "diya-gl: extension — Whether the business is VAT registered"
        },
        "diya-gl:basisOfAccounting": {
          "type": "string",
          "enum": ["cash", "accrual"],
          "default": "cash",
          "description": "diya-gl: extension — Accounting basis. Cash for sole traders, accrual for companies."
        },
        "diya-gl:nino": {
          "type": "string",
          "pattern": "^([A-Z]{2}[0-9]{6}[A-D])?$",
          "description": "diya-gl: extension — National Insurance Number (format: AB123456C)"
        },
        "diya-gl:vatNumber": {
          "type": "string",
          "pattern": "^([0-9]{9})?$",
          "description": "diya-gl: extension — VAT registration number (9 digits)"
        },
        "diya-gl:companyNumber": {
          "type": "string",
          "pattern": "^([0-9]{8})?$",
          "description": "diya-gl: extension — Companies House number (8 digits, Company Accounts only)"
        },
        "diya-gl:cisRegistered": {
          "type": "boolean",
          "default": false,
          "description": "diya-gl: extension — Whether the business is registered under the Construction Industry Scheme (CIS)"
        },
        "diya-gl:companiesHouseName": {
          "type": "string",
          "description": "diya-gl: extension — The first director's name as filed at Companies House, for the directors' report and CT600 (Company Accounts only)."
        },
        "diya-gl:mileageBasis": {
          "type": "string",
          "enum": ["actual", "mileage"],
          "description": "diya-gl: extension — Whether the Taxi Driver return claims actual vehicle costs or the HMRC mileage allowance. Where absent, the calculator compares both and claims the higher, matching the shipped workbook's own comparison."
        }
      }
    },

    "directors": {
      "type": "array",
      "description": "diya-gl: extension — Company directors and their shareholdings (Company Accounts only). Used to populate Companysecretary.xlsx sheets.",
      "items": {
        "type": "object",
        "required": ["name", "role"],
        "additionalProperties": false,
        "properties": {
          "name": {
            "type": "string",
            "description": "Director's full name"
          },
          "role": {
            "type": "string",
            "description": "Role title (e.g. Managing Director, Company Secretary, Non-Executive Director)"
          },
          "shares": {
            "type": "integer",
            "minimum": 0,
            "description": "Number of shares held"
          },
          "appointed": {
            "type": "string",
            "format": "date",
            "description": "Date of appointment (ISO 8601)"
          },
          "resigned": {
            "type": "string",
            "format": "date",
            "description": "Date of resignation if applicable (ISO 8601)"
          }
        }
      }
    },

    "employees": {
      "type": "array",
      "description": "diya-gl: extension — Employees on payroll. Used to populate Payslips.xlsx. Includes directors paid via PAYE.",
      "items": {
        "type": "object",
        "required": ["employeeID", "name", "grossPay", "payFrequency", "taxCode"],
        "additionalProperties": false,
        "properties": {
          "employeeID": {
            "type": "string",
            "description": "Unique employee identifier (matches diya-gl:employeeID in lines)"
          },
          "name": {
            "type": "string",
            "description": "Employee's full name"
          },
          "role": {
            "type": "string",
            "description": "Job title"
          },
          "grossPay": {
            "type": "number",
            "minimum": 0,
            "description": "Gross pay per period (monthly or weekly amount)"
          },
          "payFrequency": {
            "type": "string",
            "enum": ["weekly", "fortnightly", "four-weekly", "monthly"],
            "description": "Pay frequency"
          },
          "taxCode": {
            "type": "string",
            "description": "HMRC tax code (e.g. 1257L)"
          },
          "niCategory": {
            "type": "string",
            "pattern": "^[A-Z]$",
            "default": "A",
            "description": "NI category letter (A=standard, C=over state pension age, H=apprentice under 25, M=under 21)"
          },
          "startDate": {
            "type": "string",
            "format": "date",
            "description": "Employment start date (ISO 8601)"
          },
          "isDirector": {
            "type": "boolean",
            "default": false,
            "description": "Whether this employee is also a company director"
          }
        }
      }
    },

    "accounts": {
      "type": "object",
      "description": "Chart of accounts. Maps to gl-cor:account tuples. Organised by journal for spreadsheet column mapping.",
      "required": ["sales", "purchases"],
      "additionalProperties": false,
      "properties": {
        "sales": {
          "type": "object",
          "description": "Sales/income account codes. Keys are gl-cor:accountMainID values.",
          "minProperties": 1,
          "patternProperties": {
            "^[0-9]{4}$": {
              "$ref": "#/$defs/accountDefinition"
            }
          },
          "additionalProperties": false
        },

        "purchases": {
          "type": "object",
          "description": "Purchase/expense account codes. Keys are gl-cor:accountMainID values.",
          "minProperties": 1,
          "patternProperties": {
            "^[0-9]{4}$": {
              "$ref": "#/$defs/accountDefinition"
            }
          },
          "additionalProperties": false
        },

        "bank": {
          "type": "object",
          "description": "Bank/cash account codes (Company Accounts). Keys are gl-cor:accountMainID values.",
          "patternProperties": {
            "^[0-9]{4}$": {
              "$ref": "#/$defs/accountDefinition"
            }
          },
          "additionalProperties": false
        },

        "capital": {
          "type": "object",
          "description": "Capital/equity account codes (Company Accounts). Keys are gl-cor:accountMainID values.",
          "patternProperties": {
            "^[0-9]{4}$": {
              "$ref": "#/$defs/accountDefinition"
            }
          },
          "additionalProperties": false
        },

        "assets": {
          "type": "object",
          "description": "Fixed/current asset account codes (Company Accounts). Keys are gl-cor:accountMainID values.",
          "patternProperties": {
            "^[0-9]{4}$": {
              "$ref": "#/$defs/accountDefinition"
            }
          },
          "additionalProperties": false
        },

        "liabilities": {
          "type": "object",
          "description": "Liability account codes (Company Accounts). Keys are gl-cor:accountMainID values.",
          "patternProperties": {
            "^[0-9]{4}$": {
              "$ref": "#/$defs/accountDefinition"
            }
          },
          "additionalProperties": false
        }
      }
    },

    "openingBalances": {
      "type": "object",
      "description": "diya-gl: extension — The trial balance brought forward, reverse-engineered today from an opening journal by buildOpeningBalance(); this table lets a book state it directly. Every figure is positive; the balance sheet applies its own sign.",
      "additionalProperties": false,
      "properties": {
        "fixedAssetCost": { "$ref": "#/$defs/assetClassAmounts" },
        "fixedAssetDepreciation": { "$ref": "#/$defs/assetClassAmounts" },
        "stock": { "type": "number", "minimum": 0 },
        "tradeDebtors": { "type": "number", "minimum": 0 },
        "tradeCreditors": { "type": "number", "minimum": 0 },
        "longTermDebtors": { "type": "number", "minimum": 0 },
        "bankAccounts": {
          "type": "object",
          "description": "Opening balance per bank account, keyed by the account code declared in accounts.bank.",
          "patternProperties": {
            "^[0-9]{4}$": { "type": "number" }
          },
          "additionalProperties": false
        },
        "payeDue": { "type": "number" },
        "vatDue": { "type": "number" },
        "cisDue": { "type": "number" },
        "netWagesDue": { "type": "number" },
        "wageDeductionsDue": { "type": "number" },
        "corporationTaxDue": { "type": "number" },
        "dividendsDue": { "type": "number" },
        "directorsLoan": { "type": "number" },
        "longTermCreditors": { "type": "number" },
        "shareCapital": { "type": "number", "minimum": 0 },
        "retainedEarnings": { "type": "number" },
        "capitalReserves": { "type": "number" }
      }
    },

    "stock": {
      "type": "object",
      "description": "diya-gl: extension — Opening and closing stock, and the physical count taken at each. materialsPercent is the share of net sales that is direct materials; the Stock sheet's bought and sold columns stay at zero without it.",
      "additionalProperties": false,
      "properties": {
        "openingValue": { "type": "number", "minimum": 0 },
        "closingValue": { "type": "number", "minimum": 0 },
        "openingCount": { "type": "number", "minimum": 0 },
        "closingCount": { "type": "number", "minimum": 0 },
        "materialsPercent": { "type": "number", "minimum": 0, "maximum": 1 }
      }
    },

    "debtors": {
      "type": "array",
      "description": "diya-gl: extension — Named trade debtors at the opening or closing balance sheet date.",
      "items": { "$ref": "#/$defs/ledgerListing" }
    },

    "creditors": {
      "type": "array",
      "description": "diya-gl: extension — Named trade creditors at the opening or closing balance sheet date.",
      "items": { "$ref": "#/$defs/ledgerListing" }
    },

    "fixedAssets": {
      "type": "array",
      "description": "diya-gl: extension — The fixed asset register: one entry per asset held at the opening balance sheet date or bought in the year. A capital allowance's balancing allowance on disposal reads taxWrittenDownValue, not accumulatedDepreciation, because the two schedules run at different rates. class is optional: the Basic Sole Trader and Taxi Driver Fixed Assets sheets carry a flat list with no asset-class blocks, unlike the Self Employed and Company Schedule.",
      "items": {
        "type": "object",
        "required": ["assetID", "cost"],
        "additionalProperties": false,
        "properties": {
          "assetID": {
            "type": "string",
            "description": "Identifier matched by diya-gl:assetID on the lines that buy or dispose of this asset."
          },
          "class": {
            "type": "string",
            "enum": ["landBuildings", "plantMachinery", "fixturesFittings", "computerTechnology", "motorVehicles"],
            "description": "The Schedule block this asset belongs to (Self Employed and Company only)."
          },
          "description": { "type": "string" },
          "cost": { "type": "number", "minimum": 0 },
          "accumulatedDepreciation": { "type": "number", "minimum": 0 },
          "taxWrittenDownValue": {
            "type": "number",
            "minimum": 0,
            "description": "Written down value carried forward on the capital allowances computation, brought forward for an asset already held at the opening balance sheet date."
          },
          "acquiredDate": { "type": "string", "format": "date" },
          "depreciationRate": { "type": "number", "minimum": 0, "maximum": 1 },
          "disposedDate": { "type": "string", "format": "date" },
          "disposalProceeds": { "type": "number", "minimum": 0 }
        }
      }
    },

    "hpAgreements": {
      "type": "array",
      "description": "diya-gl: extension — Hire purchase agreements financing an asset over a fixed term. The HPfinance sheet works out its own monthly payment, capital and interest split from these fields.",
      "items": {
        "type": "object",
        "required": ["agreementID", "amountFinanced", "adminCharges", "totalInterest", "termMonths", "startDate"],
        "additionalProperties": false,
        "properties": {
          "agreementID": {
            "type": "string",
            "description": "Identifier matched by diya-gl:hpAgreement on the purchase line the agreement finances."
          },
          "description": { "type": "string" },
          "financeCompany": { "type": "string" },
          "supplier": { "type": "string" },
          "amountFinanced": { "type": "number", "minimum": 0 },
          "adminCharges": { "type": "number", "minimum": 0 },
          "totalInterest": { "type": "number", "minimum": 0 },
          "termMonths": { "type": "integer", "minimum": 1 },
          "startDate": { "type": "string", "format": "date" }
        }
      }
    },

    "dividends": {
      "type": "array",
      "description": "diya-gl: extension — Dividends the board declared (Company Accounts only). The directors' report and the trial balance both read the declaration; the bank pays it in one or more instalments.",
      "items": {
        "type": "object",
        "required": ["boardMeetingDate", "amount"],
        "additionalProperties": false,
        "properties": {
          "declaredDate": { "type": "string", "format": "date" },
          "boardMeetingDate": { "type": "string", "format": "date" },
          "amount": { "type": "number", "minimum": 0 }
        }
      }
    },

    "members": {
      "type": "array",
      "description": "diya-gl: extension — The register of members (Company Accounts only). A member is not always a director; directors[] holds the officers.",
      "items": {
        "type": "object",
        "required": ["memberID", "name", "shares"],
        "additionalProperties": false,
        "properties": {
          "memberID": {
            "type": "string",
            "description": "Identifier matched by diya-gl:memberID on the dividend payment lines this member receives."
          },
          "name": { "type": "string" },
          "shares": { "type": "integer", "minimum": 0 },
          "nominalValue": {
            "type": "number",
            "minimum": 0,
            "description": "Nominal value per share. The shipped register currently prices every holding at a single nominal value set for the whole company, so a per-member figure here is not yet read."
          },
          "acquiredDate": { "type": "string", "format": "date" }
        }
      }
    },

    "charges": {
      "type": "array",
      "description": "diya-gl: extension — Charges and debentures registered over the company's assets (Company Accounts only). Each secures a creditor falling due after more than one year.",
      "items": {
        "type": "object",
        "required": ["valuation"],
        "additionalProperties": false,
        "properties": {
          "chargeDate": { "type": "string", "format": "date" },
          "description": {
            "type": "string",
            "description": "The charged asset, as it reads on the register (e.g. 'Motor vehicles, being the company's delivery van')."
          },
          "valuation": { "type": "number", "minimum": 0 },
          "holder": { "type": "string" },
          "terms": { "type": "string" },
          "boardMeetingDate": { "type": "string", "format": "date" }
        }
      }
    },

    "tax": {
      "type": "object",
      "description": "Tax rates and thresholds. Values from HMRC published rates for the period. Used by validate and generate commands. Derived from gl-taf tax concepts.",
      "additionalProperties": false,
      "properties": {
        "incomeTax": {
          "type": "object",
          "description": "HMRC income tax rates and thresholds (England/Wales/NI)",
          "additionalProperties": false,
          "properties": {
            "personalAllowance": { "type": "number", "minimum": 0 },
            "personalAllowanceTaperThreshold": { "type": "number", "minimum": 0 },
            "basicRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "basicRateLimit": { "type": "number", "minimum": 0 },
            "higherRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "higherRateThreshold": { "type": "number", "minimum": 0 },
            "additionalRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "additionalRateThreshold": { "type": "number", "minimum": 0 }
          }
        },

        "nationalInsurance": {
          "type": "object",
          "description": "HMRC National Insurance rates (self-employed Class 2 + 4, employed Class 1)",
          "additionalProperties": false,
          "properties": {
            "class2WeeklyRate": { "type": "number", "minimum": 0 },
            "class2SmallProfitsThreshold": { "type": "number", "minimum": 0 },
            "class4MainRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "class4UpperRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "class4LowerProfits": { "type": "number", "minimum": 0 },
            "class4UpperProfits": { "type": "number", "minimum": 0 },
            "class1EmployeeMainRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "class1EmployeeUpperRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "class1EmployeePrimaryThreshold": { "type": "number", "minimum": 0 },
            "class1EmployeeUpperEarningsLimit": { "type": "number", "minimum": 0 },
            "class1EmployerRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "class1EmployerSecondaryThreshold": { "type": "number", "minimum": 0 },
            "employmentAllowance": { "type": "number", "minimum": 0 }
          }
        },

        "vat": {
          "type": "object",
          "description": "HMRC VAT rates and thresholds",
          "additionalProperties": false,
          "properties": {
            "standardRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "reducedRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "registrationThreshold": { "type": "number", "minimum": 0 },
            "flatRateScheme": { "type": "boolean", "default": false },
            "flatRatePercentage": { "type": "number", "minimum": 0, "maximum": 1 },
            "staggerGroup": {
              "type": "integer",
              "enum": [1, 2, 3],
              "description": "Which of HMRC's three VAT stagger groups this business's quarters fall on."
            },
            "firstPeriodEnd": {
              "type": "string",
              "format": "date",
              "description": "The end date of the first VAT return period the book's data covers, so the return cycle is data rather than inferred from the sheet's own dates."
            }
          }
        },

        "corporationTax": {
          "type": "object",
          "description": "HMRC Corporation Tax rates (Company Accounts only)",
          "additionalProperties": false,
          "properties": {
            "smallProfitsRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "smallProfitsLimit": { "type": "number", "minimum": 0 },
            "mainRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "mainRateThreshold": { "type": "number", "minimum": 0 },
            "associatedCompanies": { "type": "integer", "minimum": 0, "default": 0 }
          }
        },

        "capitalAllowances": {
          "type": "object",
          "description": "HMRC capital allowance rates",
          "additionalProperties": false,
          "properties": {
            "annualInvestmentAllowance": { "type": "number", "minimum": 0 },
            "mainRateWDA": { "type": "number", "minimum": 0, "maximum": 1 },
            "specialRateWDA": { "type": "number", "minimum": 0, "maximum": 1 },
            "firstYearAllowanceRate": { "type": "number", "minimum": 0, "maximum": 1 }
          }
        },

        "mileage": {
          "type": "object",
          "description": "HMRC approved mileage rates (Taxi Driver / Self Employed)",
          "additionalProperties": false,
          "properties": {
            "carFirst10000": { "type": "number", "minimum": 0, "description": "Rate per mile, first 10,000 miles" },
            "carOver10000": { "type": "number", "minimum": 0, "description": "Rate per mile, above 10,000 miles" },
            "motorcycle": { "type": "number", "minimum": 0 },
            "bicycle": { "type": "number", "minimum": 0 }
          }
        },

        "dividends": {
          "type": "object",
          "description": "Dividend tax rates (Company Accounts — director extraction)",
          "additionalProperties": false,
          "properties": {
            "allowance": { "type": "number", "minimum": 0 },
            "basicRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "higherRate": { "type": "number", "minimum": 0, "maximum": 1 },
            "additionalRate": { "type": "number", "minimum": 0, "maximum": 1 }
          }
        }
      }
    }
  },

  "$defs": {
    "accountDefinition": {
      "type": "object",
      "description": "Definition of a single account in the chart of accounts. Maps to gl-cor:account tuple.",
      "required": ["accountMainDescription"],
      "additionalProperties": false,
      "properties": {
        "accountMainDescription": {
          "type": "string",
          "description": "gl-cor:accountMainDescription — Human-readable account name"
        },
        "accountType": {
          "type": "string",
          "enum": ["account", "bank", "customer", "vendor", "employee", "job", "statistical", "measurable", "other"],
          "default": "account",
          "description": "gl-bus:accountType — GL account type enumeration"
        },
        "diya-gl:column": {
          "type": "string",
          "pattern": "^[A-Z]{1,2}$",
          "description": "diya-gl: extension — Excel column letter(s) for this account in the workbook"
        },
        "diya-gl:sa103sBox": {
          "type": "string",
          "pattern": "^box[0-9]{1,2}$",
          "description": "diya-gl: extension — SA103S box reference this account maps to (e.g. 'box10')"
        },
        "diya-gl:ct600Box": {
          "type": "string",
          "description": "diya-gl: extension — CT600 box reference (Company Accounts only)"
        },
        "diya-gl:vatBox": {
          "type": "integer",
          "minimum": 1,
          "maximum": 9,
          "description": "diya-gl: extension — VAT return box number (1-9) this account contributes to"
        }
      }
    },

    "assetClassAmounts": {
      "type": "object",
      "description": "An amount per fixed asset class.",
      "additionalProperties": false,
      "properties": {
        "landBuildings": { "type": "number", "minimum": 0 },
        "plantMachinery": { "type": "number", "minimum": 0 },
        "fixturesFittings": { "type": "number", "minimum": 0 },
        "computerTechnology": { "type": "number", "minimum": 0 },
        "motorVehicles": { "type": "number", "minimum": 0 }
      }
    },

    "ledgerListing": {
      "type": "object",
      "description": "One named debtor or creditor balance.",
      "required": ["counterparty", "amount", "timing"],
      "additionalProperties": false,
      "properties": {
        "counterparty": { "type": "string" },
        "invoice": { "type": "string" },
        "amount": { "type": "number", "minimum": 0 },
        "timing": { "type": "string", "enum": ["opening", "closing"] }
      }
    }
  }
}