You can define encumbrance accounting or budgetary control in Financial options window:
Navigation: AP or PO —-> Setup–> Organizations –> Financial Options.

In order to use encumbrance accounting or budgetary control, you must install Payables, Purchasing, and General Ledger modules. You may go to encunbrance region to enable encumbrance accounting and to specify the default encumbrance types which Payables module assigns to your invoices, and Purchasing module assigns to your requisitions and purchase orders.

If you enable encumbrance accounting or budgetary control, Purchasing creates
encumbrances when you reserve funds for a requisition or purchase order. If you use the perpetual accrual method in Purchasing, it reverses the purchase order encumbrances when you inspect, accept, and deliver the units. If you are using the periodic accrual method in Purchasing, Payables reverses the purchase order encumbrances when you create accounting entries for invoices. Payables module creates encumbrances when there is a variance between a matched invoice and the purchase order to which it is matched, and when the invoice encumbrance type is different from the Purchasing encumbrance type.

Oracle EBS provides two predefined encumbrance types that you can use to identify requisition, purchase order, and invoice encumbrances:- Commitment and
Obligation. You can define additional encumbrance types in Oracle General Ledger module in the Encumbrance Types window.

1) Use Requisition Encumbrance
You may enable this option to encumber funds for requisitions. If you enable this option, Purchasing creates journal entries and transfers them to General Ledger to encumber funds for purchase requisitions.

If you enable Use Requisition Encumbrance, you must select an encumbrance type by which you can identify your requisition encumbrance journal entries. Purchasing assigns this encumbrance type to the encumbrance journal entries it creates for purchase requisitions. If you enable Use Requisition Encumbrance, you can indicate whether you want requisition preparer to have the option to reserve funds. If you do not enable this option, only requisition approvers will have the option to reserve funds.

2)Use PO Encumbrance
Enable this option to encumber funds for purchase orders, purchase order and receipt matched invoices, and basic invoices (not matched). If you enable this option, Purchasing encumbers funds for purchase orders and Payables encumbers funds for variances during Payables Invoice Validation for purchase order and receipt matched invoices. If you enable this option and enter a non-purchase order matched invoice, Payables will encumber funds for it during Payables Invoice Validation. All Payables encumbrances are reversed when you create accounting entries. If you enable Use Requisition Encumbrance, you must also enable this option.

If you enable Use Purchase Order Encumbrance, select a purchase order encumbrance type by which you can identify your purchase order encumbrance journal entries. Purchasing assigns this encumbrance type to the encumbrance journal entries it creates for purchase requisitions and purchase orders. If you use purchase order encumbrance, select an invoice encumbrance type by which you can identify your invoice encumbrance journal entries. Payables module assigns this encumbrance type to the encumbrance journal entries that it creates. It is recommended that you use an encumbrance type different from the Purchasing encumbrance type so you can identify invoice encumbrances

11i and R12

In 11i the field ‘bank_account_id’ acts as a relation key between the AP_CHECKS_ALL and AP_BANK_ACCOUNTS_ALL tables.

In 12 i the same field is no longer is used in ‘AP_CHECKS_ALL’ table.

In 12 i where ‘CE_BANK_ACCT_USE_ID’ is acts as a relation between ‘CE_BANK_ACCT_USES_ALL’ and ‘AP_CHECKS_ALL’

Highlights of release 12i

A single responsibility to access and transact on multiple organizations.
A single ledger to manage multiple currencies.
Ledger sets to manage accounting processes across ledger.
Centralized rules engines for tax, accounting and Intercomapny.
Centralized trading partners i.e Suppliers, Banks, First Party legal entities.
Simplified reporting via XML Publisher and DBI.
Netting across trading partners.

Steps to Perform India localization in R12
The following table lists setup steps required for India localization.
When we Purchase some material/Goods/Items from Vendor/Supplier, after receiving the material. Vendor would send the INVOICE (In other words we receive BILL for the Items you have received). And payment will be done automatically. If there is some Discrepancy in the Items received and in the BILL/INVOICE you received, for them to hold the payment we normally set the HOLD rules. From the following Query you can know the Hold reason at the Summary level. 

select * from
(SELECT api.invoice_id, api.invoice_date AS invoice_date,
api.invoice_num AS invoice_num, pov.vendor_id AS vendor_id,
pov.vendor_name AS supplier_name, apd.inv_lines AS total_inv_lines,
NVL (hold_tab_info.hold_inv_lines, 0) AS total_line_holds,
NVL (CEIL ((hold_tab_info.hold_inv_lines * 100) / DECODE(apd.inv_lines,0,1,apd.inv_lines)),
0
) AS percentage_line_hold,
DECODE (hold_tab_info.hold_inv_lines,
NULL, ‘N’,
0, ‘N’,
‘Y’
) AS defect,
DECODE (hold_tab_info.hold_inv_lines,
NULL, 0,
0, 0,
1
) AS defect_count, 1 inv_count,
NVL (hold_count.hold_cnt, 0) AS total_inv_holds,
NVL (c.hold_os, 0) AS days_outstanding,
NVL (api.invoice_amount, 0) AS total_invoice_amount,
NVL (hold_tab_info.hold_amount, 0) AS total_hold_amount,
NVL (CEIL ((hold_tab_info.hold_amount * 100) / DECODE(api.invoice_amount,0,1,api.invoice_amount)),
0
) AS percentage_amount_hold
FROM APPS.ap_invoices_all api,
(SELECT invoice_id, COUNT (invoice_id) inv_lines
FROM APPS.ap_invoice_distributions_all
GROUP BY invoice_id) apd,
(SELECT invoice_id, COUNT (hold_lookup_code) hold_cnt
FROM APPS.ap_holds_all
WHERE 1 = 1 AND line_location_id IS NOT NULL
GROUP BY invoice_id) hold_count,
(SELECT invoice_id, COUNT (hold_tab.line_num) hold_inv_lines,
SUM (hold_tab.hold_amount) hold_amount
FROM (SELECT DISTINCT api.invoice_id invoice_id,
apd.distribution_line_number line_num,
apd.amount hold_amount
FROM APPS.ap_invoices_all api,
APPS.ap_invoice_distributions_all apd,
APPS.po_distributions_all pod,
APPS.ap_holds_all aph
WHERE 1 = 1
AND api.invoice_id = apd.invoice_id
AND aph.invoice_id(+) = api.invoice_id
AND api.cancelled_date IS NULL
AND apd.po_distribution_id = pod.po_distribution_id(+)
AND aph.line_location_id = pod.line_location_id
AND aph.line_location_id IS NOT NULL) hold_tab
GROUP BY invoice_id) hold_tab_info,
(SELECT invoice_id, MAX (b.hold_os) hold_os
FROM (SELECT invoice_id,
DECODE (status_flag,
‘R’, ( TRUNC (NVL (last_update_date,
SYSDATE)
)
– TRUNC (hold_date)
),
(TRUNC (SYSDATE) – TRUNC (hold_date))
) hold_os
FROM APPS.ap_holds_all
WHERE line_location_id IS NOT NULL) b
GROUP BY invoice_id) c,
APPS.po_vendors pov
WHERE 1 = 1
AND hold_tab_info.invoice_id(+) = api.invoice_id
AND c.invoice_id(+) = api.invoice_id
AND api.invoice_id = apd.invoice_id
AND api.vendor_id = pov.vendor_id(+)
AND api.cancelled_date IS NULL
AND api.invoice_id = hold_count.invoice_id(+))
where invoice_num=’Your Invoice number’;

When we Purchase some material/Goods/Items from Vendor/Supplier, after receiving the material. Vendor would send the INVOICE (In other words we receive BILL for the Items you have received). And payment will be done automatically. If there is some Discrepancy in the Items received and in the BILL/INVOICE you received, for them to hold the payment we normally set the HOLD rules. From the following Query you can know the Hold reason at the detail level.

Note:- Normally this kind of Information will be required for the Top level management for the decision making.

select * from
(SELECT ‘Holds – Source1’ AS SOURCE, 
api.invoice_date AS invoice_date,
api.invoice_num AS invoice_num, 
pov.vendor_name AS supplier_name,
apd.distribution_line_number AS inv_line_num,
apd.amount AS invoice_line_amount,
DECODE (aph.hold_reason, NULL, ‘N’, ‘Y’) AS defect,
poh.segment1 AS po_number, 
por.release_num AS po_release_num,
pol.line_num AS po_line_num, 
aph.hold_date AS hold_date,
aph.hold_lookup_code AS hold_lookup_code,
aph.hold_reason AS hold_reason, 
aph.last_update_date AS release_date,
(TRUNC (NVL (aph.last_update_date, SYSDATE)) – TRUNC (aph.hold_date)) AS days_os,
pod.quantity_ordered AS shipment_quantity_ordered,
pod.quantity_delivered AS shipment_quantity_delivered,
pod.quantity_billed AS shipment_quantity_billed,
api.invoice_received_date AS invoice_received_date,
pob.agent_name AS buyer, 
povs.vendor_site_code AS supplier_site,
ppf.full_name AS requestor, 
rcvh.receipt_num AS receipt_number,
rcv.quantity AS received_accepted_qty, 
rcv.unit_of_measure AS uom,
rcv.creation_date AS receipt_transacted_date,
rcv.transaction_date AS receipt_date
FROM APPS.ap_invoices_all api,
APPS.ap_invoice_distributions_all apd,
APPS.po_distributions_all pod,
APPS.po_headers_all poh,
APPS.po_releases_all por,
APPS.po_lines_all pol,
APPS.ap_holds_all aph,
APPS.po_vendors pov,
APPS.po_agents_v pob,
APPS.po_vendor_sites_all povs,
APPS.rcv_transactions rcv,
APPS.rcv_shipment_headers rcvh,
APPS.po_line_locations_all pll,
APPS.hr_locations_all loc,
APPS.per_all_people_f ppf
WHERE 1 = 1
AND api.invoice_id = apd.invoice_id
AND aph.invoice_id(+) = api.invoice_id
AND api.vendor_id = pov.vendor_id(+)
AND api.cancelled_date IS NULL
AND apd.po_distribution_id = pod.po_distribution_id(+)
AND aph.line_location_id = pod.line_location_id
AND poh.po_header_id(+) = pod.po_header_id
AND por.po_release_id(+) = pod.po_release_id
AND pol.po_header_id (+) = pod.po_header_id —
AND pol.po_line_id (+) = pod.po_line_id 
AND poh.agent_id = pob.agent_id(+)
AND povs.vendor_site_id(+) = poh.vendor_site_id
AND apd.po_distribution_id = rcv.po_distribution_id(+)
AND rcvh.shipment_header_id(+) = rcv.shipment_header_id
AND rcv.destination_type_code(+) = ‘RECEIVING’
AND pll.line_location_id(+) = pod.line_location_id
AND pll.ship_to_location_id = loc.location_id(+)
AND pod.deliver_to_person_id = ppf.person_id (+)
AND NVL (ppf.effective_start_date, SYSDATE) <= SYSDATE
AND NVL (ppf.effective_end_date, SYSDATE + 1) > SYSDATE
UNION
SELECT ‘Holds NotLinked To PO-Source2’ AS SOURCE,
api.invoice_date AS invoice_date, api.invoice_num AS invoice_num,
pov.vendor_name AS supplier_name,
apd.distribution_line_number AS inv_line_num,
apd.amount AS invoice_line_amount,
DECODE (aph.hold_reason, NULL, ‘N’, ‘Y’) AS defect,
poh.segment1 AS po_number, por.release_num AS po_release_num,
pol.line_num AS po_line_num, aph.hold_date AS hold_date,
aph.hold_lookup_code AS hold_lookup_code,
aph.hold_reason AS hold_reason, aph.last_update_date AS release_date,
(TRUNC (NVL (aph.last_update_date, SYSDATE)) – TRUNC (aph.hold_date)
) AS days_os,
pod.quantity_ordered AS shipment_quantity_ordered,
pod.quantity_delivered AS shipment_quantity_delivered,
pod.quantity_billed AS shipment_quantity_billed,
api.invoice_received_date AS invoice_received_date,
pob.agent_name AS buyer, povs.vendor_site_code AS supplier_site,
ppf.full_name AS requestor, rcvh.receipt_num AS receipt_number,
rcv.quantity AS received_accepted_qty, rcv.unit_of_measure AS uom,
rcv.creation_date AS receipt_transacted_date,
rcv.transaction_date AS receipt_date
FROM APPS.ap_invoices_all api,
APPS.ap_invoice_distributions_all apd,
APPS.po_distributions_all pod,
APPS.po_headers_all poh,
APPS.po_releases_all por,
APPS.po_lines_all pol,
APPS.ap_holds_all aph,
APPS.po_vendors pov,
APPS.po_agents_v pob,
APPS.po_vendor_sites_all povs,
APPS.rcv_transactions rcv,
APPS.rcv_shipment_headers rcvh,
APPS.po_line_locations_all pll,
APPS.hr_locations_all loc,
APPS.per_all_people_f ppf
WHERE 1 = 1
AND api.invoice_id = apd.invoice_id
AND aph.invoice_id(+) = api.invoice_id
AND api.vendor_id = pov.vendor_id(+)
AND api.cancelled_date IS NULL
AND apd.po_distribution_id = pod.po_distribution_id(+)
AND aph.line_location_id = pod.line_location_id
AND aph.line_location_id IS NULL
AND poh.po_header_id(+) = pod.po_header_id
AND por.po_release_id(+) = pod.po_release_id
AND pol.po_header_id(+) = pod.po_header_id
AND pol.po_line_id(+) = pod.po_line_id
AND poh.agent_id = pob.agent_id(+)
AND povs.vendor_site_id(+) = poh.vendor_site_id
AND apd.po_distribution_id = rcv.po_distribution_id(+)
AND rcvh.shipment_header_id(+) = rcv.shipment_header_id
AND rcv.destination_type_code(+) = ‘RECEIVING’
AND pll.line_location_id(+) = pod.line_location_id
AND pll.ship_to_location_id = loc.location_id(+)
AND pod.deliver_to_person_id = ppf.person_id(+)
AND NVL (ppf.effective_start_date, SYSDATE) <= SYSDATE
AND NVL (ppf.effective_end_date, SYSDATE + 1) > SYSDATE
UNION
SELECT ‘NON Holds – Source 3’ AS SOURCE, apii.invoice_date AS invoice_date,
apii.invoice_num AS invoice_num, pov.vendor_name AS supplier_name,
apd.distribution_line_number AS inv_line_num,
apd.amount AS invoice_line_amount, ‘N’ AS defect,
poh.segment1 AS po_number, por.release_num AS po_release_num,
pol.line_num AS po_line_num, NULL AS hold_date,
NULL AS hold_lookup_code, NULL AS hold_reason, NULL AS release_date,
0 AS days_os, pod.quantity_ordered AS shipment_quantity_ordered,
pod.quantity_delivered AS shipment_quantity_delivered,
pod.quantity_billed AS shipment_quantity_billed,
apii.invoice_received_date AS invoice_received_date,
pob.agent_name AS buyer, povs.vendor_site_code AS supplier_site,
ppf.full_name AS requestor, rcvh.receipt_num AS receipt_number,
rcv.quantity AS received_accepted_qty, rcv.unit_of_measure AS uom,
rcv.creation_date AS receipt_transacted_date,
rcv.transaction_date AS receipt_date
FROM APPS.ap_invoices_all apii,
APPS.ap_invoice_distributions_all apd,
APPS.po_distributions_all pod,
APPS.po_headers_all poh,
APPS.po_releases_all por,
APPS.po_lines_all pol,
APPS.po_vendors pov,
APPS.po_agents_v pob,
APPS.po_vendor_sites_all povs,
APPS.rcv_transactions rcv,
APPS.rcv_shipment_headers rcvh,
APPS.po_line_locations_all pll,
APPS.hr_locations_all loc,
APPS.per_all_people_f ppf
WHERE 1 = 1
AND apii.invoice_id = apd.invoice_id
AND apii.vendor_id = pov.vendor_id(+)
AND apii.cancelled_date IS NULL
AND apd.po_distribution_id = pod.po_distribution_id(+)
AND apd.distribution_line_number NOT IN (
SELECT apd.distribution_line_number
FROM APPS.ap_invoices_all api,
APPS.ap_invoice_distributions_all apd,
APPS.po_distributions_all pod,
APPS.ap_holds_all aph
WHERE 1 = 1
AND api.invoice_id = apd.invoice_id
AND aph.invoice_id(+) = api.invoice_id
AND api.cancelled_date IS NULL
AND apd.po_distribution_id = pod.po_distribution_id(+)
AND aph.line_location_id = pod.line_location_id
AND api.invoice_id = apii.invoice_id)
AND poh.po_header_id(+) = pod.po_header_id
AND por.po_release_id(+) = pod.po_release_id
AND pol.po_header_id(+) = pod.po_header_id
AND pol.po_line_id(+) = pod.po_line_id
AND poh.agent_id = pob.agent_id(+)
AND povs.vendor_site_id(+) = poh.vendor_site_id
AND apd.po_distribution_id = rcv.po_distribution_id(+)
AND rcvh.shipment_header_id(+) = rcv.shipment_header_id
AND rcv.destination_type_code(+) = ‘RECEIVING’
AND pll.line_location_id(+) = pod.line_location_id
AND pll.ship_to_location_id = loc.location_id(+)
AND pod.deliver_to_person_id = ppf.person_id(+)
AND NVL (ppf.effective_start_date, SYSDATE) <= SYSDATE
AND NVL (ppf.effective_end_date, SYSDATE + 1) > SYSDATE)
where invoice_num=’Your Invoice number’