Supposed that there is a service type company, they have received whole money from their customer, but they have not provided the whole service finally. The whole service will be provided within 12 months from current month. Against accrual basis concept, the company can’t recognize revenue for the whole money amount to current month, even though they received whole money in current month.
Multi Period Accounting (MPA) enables users to create accounting for a single accounting event for more than one GL period. This functionality is primarily used to recognize revenue or a prepaid expense across multiple GL periods.
Within Multi Period Accounting, application provides different ways to Prorate the amounts.
- First Period
- Days In Period
- Total Days In Period
- 360 Days
The Amount prorated depends on the Proration Type.
Here are some of documentation for further deep dive :
Subledger Accounting , White Paper on Multi Period Accounting (MPA) in R12
Slidershare presentation – http://www.slideshare.net/prithis/multiperiod-accounting-in-oracle-ebs-r12 ( By Prithis Das )
Deep Dive blogs articles – http://www.yunning.net/blog/?s=mpa&submit=Search
R12: Subledger Accounting: White Paper Explaining Different Proration Types in Multi Period Accounting – https://support.oracle.com/epmos/faces/DocumentDisplay?id=1915795.1
know-oracle.com 
Here’s a query that is helpful to track the entries. Hope you find it helpful.
SELECT /*+ index(b XLA_AE_LINES_U1) */
a.ae_header_id “JE Header ID”,
b.ae_line_num “JE Line Num”,
a.accounting_date,
a.period_name,
g.project_id,
g.task_id,
g.expenditure_type,
j.vendor_name,
c.invoice_num “INV NUM”,
g.invoice_line_number “INV LINE NUM”,
h.name “Exp Org Name”,
d.segment1,
d.segment2,
d.segment3,
d.segment4,
d.segment5,
d.segment6,
d.segment7,
nvl2(b.accounted_dr,g.amount,null),
nvl2(b.accounted_cr,g.amount,null),
i.deferred_acctg_flag,
i.def_acctg_start_date,
i.def_acctg_end_date,
i.attribute8 “DFF Entity”,
i.attribute3 “DFF BU”,
i.attribute2 “DFF Dept”,
i.attribute1 “DFF Account”,
b.accounting_class_code
FROM xla_ae_headers a,
xla_ae_lines b,
ap_invoices_all c,
gl_code_combinations_kfv d,
xla_transaction_entities e,
xla_distribution_links f,
ap_invoice_distributions_all g,
hr_organization_units h,
ap_invoice_lines_all i,
po_vendors j
WHERE a.accounting_entry_status_code = ‘F’
AND a.gl_transfer_status_code = ‘Y’
AND a.ae_header_id = b.ae_header_id
AND b.attribute15 IS NULL
–AND c.invoice_id = 3890571
and c.invoice_num = ‘1234.3’
and j.vendor_name = ‘Agosto Inc’
AND c.invoice_id = e.source_id_int_1
AND c.invoice_id = i.invoice_id
AND i.invoice_id = g.invoice_id
AND i.line_number = g.invoice_line_number
and c.vendor_id = j.vendor_id
AND i.deferred_acctg_flag = ‘Y’
AND e.entity_code = ‘AP_INVOICES’
AND d.code_combination_id = b.code_combination_id
— DECODE (b.accounting_class_code,
— ‘LIABILITY’, g.dist_code_combination_id,
— b.code_combination_id)
AND b.ae_header_id = f.ae_header_id
AND b.ae_line_num = f.ae_line_num
AND f.application_id = 200
AND b.application_id = 200
AND e.application_id = 200
AND f.applied_to_dist_id_num_1 = g.invoice_distribution_id
AND g.expenditure_organization_id = h.organization_id
order by a.period_name, b.ae_header_id, b.ae_line_num;
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