What it means
In the 1970s, moving money across borders was slow, taxed, or outright restricted. Britain, for example, imposed exchange controls that made it expensive for British firms to fund overseas operations.
The parallel loan offered a neat workaround. A British parent would lend pounds to the UK subsidiary of an American firm, while the American parent lent dollars to the British firm's US subsidiary.
Each loan stayed inside its own country and currency, so no money crossed a border and the exchange controls were never triggered. The two loans were matched in size and maturity by reference to the exchange rate, and each side serviced its local borrowing with local earnings.
The structure had obvious weaknesses. Two separate loan agreements meant two separate default risks: if one party failed, the other still owed its side unless extra clauses tied the loans together.
Documentation was heavy and finding a counterparty with mirror-image needs was slow. Those frictions pushed banks to design the back-to-back loan and then the currency swap, which packages the same economics into a single contract.
Official histories of the swap market, including a Bank for International Settlements working paper on the origins of central bank swaps, trace how these private parallel and back-to-back arrangements of the 1970s evolved into today's huge swap markets. Parallel loans are now rare outside countries with tight capital controls, but they still matter as a case study in financial engineering: when rules block a path, contracts get invented to walk around it.
For a non-finance owner, the lesson is that financing is about matching needs. Two firms with opposite problems solved both by exchanging obligations instead of exchanging money across a border.
The arrangement also had a tax angle. Interest on local loans was handled under local rules, which made the structure cleaner for treasurers than a single cross-border facility subject to withholding taxes and central bank approvals.
In practice
Real-world examples.
Example
A 1970s British parent funds a US expansion by lending pounds to an American firm's UK arm while the American parent lends dollars to the British firm's US arm.
Example
Two multinationals with mirror-image funding needs sign matched parallel loans, each documented locally, avoiding the premium that exchange controls charged on outbound investment.
Example
After capital controls are lifted, companies replace their parallel loans with currency swaps, which combine both legs into one contract with a single default framework.
Formula
Calculation
Loan sizes are matched at the prevailing exchange rate: if a British firm needs the equivalent of $10 million and the rate is $2 per pound, it lends 5 million pounds in London while the American counterparty lends $10 million in New York, for matching maturities and interest terms.
Worked example of servicing: suppose the pound loan carries 12% interest and the dollar loan 9%. Each year the American group's UK subsidiary pays 5,000,000 x 12% = 600,000 pounds, and the British group's US subsidiary pays $10,000,000 x 9% = $900,000. Each payment stays inside its own country and currency, so no money crosses a border, and the difference between the two interest bills reflects the interest-rate gap between the two currencies.
The structure still carries exchange-rate exposure. If the rate falls to $1.60 per pound, the 5 million pound loan is worth only 5,000,000 x $1.60 = $8 million against the $10 million dollar loan, a gap of $2 million that the pound lender bears unless the agreement includes adjustment clauses. This is one reason documentation was heavy and counterparties hard to match.Case study
Seen in the real world.
This case study is fictional and illustrative. In 1978, the made-up British engineering group Calder & Wrenn wanted dollars for its new Ohio plant, but UK exchange controls made sending capital abroad costly. Across the Atlantic, the fictional US toolmaker Beacon Forge wanted pounds for a Birmingham facility.
Their banks arranged a parallel loan: Calder lent 6 million pounds to Beacon's UK subsidiary in London, and Beacon lent 12 million dollars to Calder's Ohio subsidiary, each for five years at local market rates. Neither payment crossed a border, both subsidiaries serviced their local loans from local revenues, and each group got the funding it needed within the rules. When exchange controls were later abolished, the companies refinanced through a simple currency swap, the parallel loan's more efficient descendant.
Watch out
Common mistakes.
- Treating a parallel loan as one safe transaction, when it is really two separate loans; unless cross-default clauses link them, one side can fail while the other must keep paying.
- Ignoring the credit risk of the counterparty, since the whole structure depends on both parents honouring their respective loans for the full term.
- Assuming parallel loans are still the standard tool; currency swaps have largely replaced them because one contract is simpler, cheaper, and easier to hedge or unwind.
Questions
People also ask.
Why were parallel loans invented?
To bypass exchange controls and cross-border costs in the 1970s, letting companies fund foreign operations without physically moving money across borders.
How is a parallel loan different from a currency swap?
A parallel loan is two separate loan agreements between two parties' subsidiaries, while a currency swap is a single contract exchanging principal and interest streams in two currencies.
Are parallel loans still used?
Rarely; they survive mainly where capital controls remain tight, having been superseded elsewhere by currency swaps and direct cross-border lending.
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