# Tracking Documentation on Accounting Transactions

While [[double entry accounting|UseCases/DoubleEntryAccounting]] transactions
are the heart of any accounting system, auditors and managers need the
ability to dig down and determine what contracts, invoices, receipts or other
backup documentation relate to a given accounting document.

<a id="document-link-up"></a>
An adequate accounting system should provide easy link-up between
double-entry accounting transactions and the documentation that relates to
the transactions.  For example,
[[expense reports and reimbursement requests|UseCases/ReimbursementRequest]]
often have a myriad of receipts and invoices associated with them.
[[Handling contractors|UseCases/ContractorsAndContracts]] has similar types
of backup documentation.

Ideally, the system should allow the exploration of and linkage to
documentation in both directions.  It should be trivial to answer questions
such as:<a id="document-link-explore"></a>

   * I have this receipt/invoice from our document repository.  Which
     accounting transactions relate to this receipt?  Has the transaction
     been [[reimbursed|UseCases/ReimbursementRequest]]?

   * Looking at this invoice, can I see the transaction where it was accrued
     and paid?

   * Show me a list of invoices that haven't been paid, with links to those
     invoices.

   * Who approved this expense or payment?  Show me the email where they
     approved it.