（Obtaining or Offering of Accounting Documents）
All accounting events must have sufficient documentation provided or given.

（Categories of Accounting Documents）
Business entity accounting documents are divided into the following two categories:
1. Source document: The documents which prove the course of an event, based on which bookkeeping slips are prepared.
2. Bookkeeping slip: The documents, which prove the responsibilities of the person handling accounting events and serve as the basis for account keeping.

（Source Documents）
Categories of source documents are set as follows:
1. External document: those obtained from persons other than the business itself.
2. Outgoing document: those given to persons other than the business itself.
3. Internal documents: those prepared and kept by the business itself.

（Bookkeeping Slip）
Categories of bookkeeping slips are set as follows:
1. Receipt Slip.
2. Payment Slip.
3. Transfer Slip.
The term "transfer slip" referred to in the preceding paragraph may be classified into cash transfer slip and journal transfer slip. All the slips may be distinguished from one another by color or other means.

（Making of Slips）
Businesses must record transactions based on bookkeeping slips and prepare bookkeeping slips based on the source documents. However, for closing adjustments and post-closing transfers, the source documents may be waived.
Where the business entity accounting affairs are simple or where the source documents have met the requirements for account keeping, the source documents may be accepted in lieu of bookkeeping slip.

（Making of Source Documents）
External accounting events must be supported by external or outgoing documents. Internal accounting events must be supported by internal documents.
If a source document cannot be obtained due to restrictions or if such documents are damaged, destroyed, unavailable, or lost, in addition to handling according to the procedures under laws and regulations, a business must prepare a slip based on the fact and amount and have its person-in-charge or a designated person sign or seal for account keeping.
For an accounting event for which the source document cannot be obtained, the person-in-charge of the business may order the personnel handling and in charge of the matter to severally or jointly prove such event.