VAT Invoice Gap Check

Find gaps and duplicates in supplied VAT invoice numbers.

Description

Invoice-number continuity can reveal missing or duplicate records within an observed sequence.

Invoice-number continuity can reveal missing or duplicate records within an observed sequence. A gap audit is separate from checking invoice content and VAT treatment.^[1]

Find gaps and duplicates in supplied VAT invoice numbers.

When to use VAT Invoice Gap Check

Use this tool to find gaps and duplicates in supplied VAT invoice numbers.

Choose the specific arithmetic or checklist scenario and establish its input amounts, dates, rates and criteria from the applicable records. Keep currencies, periods and jurisdictions consistent; review the tool-specific assumptions before interpreting the result.

How to use VAT Invoice Gap Check and understand its results

Choose the specific arithmetic or checklist scenario and establish its input amounts, dates, rates and criteria from the applicable records. Keep currencies, periods and jurisdictions consistent; review the tool-specific assumptions before interpreting the result.
Enter invoiceNumbers using the field table and calculation rules, then run the tool.
Read missingInvoiceNumbers, duplicateInvoiceNumbers, gapCount, duplicateCount. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
invoiceNumbers	Invoice numbers	list of number	Required

Enter a nonempty list of nonnegative safe-integer invoice numbers. Sort a copy, return distinct duplicate numbers and enumerate absent integers between the smallest and largest observed numbers.

missing={integers from minimum to maximum not present}; duplicates={numbers occurring more than once}

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
missingInvoiceNumbers	Missing invoice numbers	list of number
duplicateInvoiceNumbers	Duplicate invoice numbers	list of number
gapCount	Missing-number count	integer; minimum: 0
duplicateCount	Duplicate-number count	integer; minimum: 0

json

{
  "input": {
    "invoiceNumbers": [
      100,
      101,
      101,
      103
    ]
  },
  "output": {
    "missingInvoiceNumbers": [
      102
    ],
    "duplicateInvoiceNumbers": [
      101
    ],
    "gapCount": 1,
    "duplicateCount": 1
  }
}

Limitations and assumptions

Use compact numeric sequences: the implementation examines every integer across the observed span. It does not inspect prefixes, separate series, dates or records outside the observed endpoints.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Payroll Reporting Coverage: Compare required payroll reporting duties with duties assigned to the payroll agent. For a complementary task, use Transcript Requirement Match: Match required tax transcript types against available records.

References

VAT Invoice Gap Check — tool.io

Similar or alternative tools

Payroll Reporting Coverage
Compare required payroll reporting duties with duties assigned to the payroll agent.
Transcript Requirement Match
Match required tax transcript types against available records.