Merchant Rates, Exchange Margins and TT or Bill Rates for CAIIB BFM

Introduction

Banks deal in foreign exchange at two broad levels.

The interbank market is where banks deal with other banks and market participants. The rates available in this market form the basis for pricing customer transactions.

When a bank quotes an exchange rate to a customer for an import, export, remittance or another permitted foreign-exchange transaction, the rate is generally called a merchant rate.

For CAIIB BFM, the main merchant rates are:

• TT buying rate

• TT selling rate

• Bill buying rate

• Bill selling rate

The difficult part is usually not the arithmetic. The real challenge is deciding which rate applies and whether the bank is buying or selling foreign currency.

Exchange margins, forward adjustments and the timing of receipt or payment of foreign currency may then affect the final rate.

The current CAIIB BFM syllabus continues to cover foreign-exchange arithmetic and merchant transactions within Exchange Rates and Forex Business.

Learning Objectives

After studying this topic, you should be able to:

• understand the meaning of a merchant exchange rate;

• distinguish between bank buying and bank selling transactions;

• identify TT buying, TT selling, bill buying and bill selling transactions;

• understand how exchange margins affect customer rates;

• identify when the timing of foreign-currency realisation affects a buying rate;

• avoid common CAIIB mistakes in merchant-rate calculations.

Core Concept: Interbank Rate vs Merchant Rate

An interbank rate is a rate at which banks deal in foreign exchange with each other.

A merchant rate is the rate quoted by a bank to its customer.

The two are not normally identical because customer pricing may reflect:

• exchange margin;

• transaction type;

• maturity or realisation period;

• forward premium or discount, where relevant;

• operational costs and pricing policy;

• market conditions.

For CAIIB numerical questions, the question generally provides the required interbank rate, exchange margin and any forward differential needed to derive the merchant rate.

Do not assume an exchange-margin percentage unless it is given.

The Most Important Rule: Think from the Bank's Side

Before choosing a rate, ask:

Is the bank buying foreign currency or selling foreign currency?

This single question solves a large part of merchant-rate arithmetic.

Bank Buying Foreign Currency

The bank is buying foreign currency when it receives foreign currency from the customer and gives rupees.

Examples include:

• inward foreign remittance payable to a customer;

• export proceeds received;

• purchase or negotiation of an export bill.

For a direct quotation such as USD/INR, the buying side of the market quotation is relevant.

Bank Selling Foreign Currency

The bank is selling foreign currency when the customer gives rupees and requires foreign currency.

Examples include:

• outward remittance;

• issue of foreign-currency payment;

• payment of an import bill.

The selling side of the market quotation is relevant.

Four Important Merchant Rates

The words TT and Bill are important.

TT broadly relates to a clean transfer where documentary credit is not being purchased by the bank and foreign-currency proceeds are available without the realisation delay associated with a purchased export bill.

Bill rates apply to relevant documentary transactions.

However, in modern banking operations, individual banks may publish or operationally apply the same rate for some categories. For CAIIB numerical questions, always use the transaction classification and margins specifically given in the question rather than assuming that every bank maintains a fixed difference between TT and bill rates.

TT Buying Rate

The TT buying rate applies when the bank buys foreign currency and there is no future realisation period that has to be built into the exchange rate in the manner applicable to a purchased export bill.

A common case is where foreign currency has already been received or credited to the bank's Nostro account and the rupee equivalent has to be paid to the beneficiary.

Typical examples include:

• inward remittance;

• foreign-currency proceeds already credited to Nostro;

• proceeds of a bill earlier sent for collection after receipt;

• other clean foreign-currency receipts;

• cancellation of certain earlier forex sale transactions, depending on the transaction terms.

TT Buying Rate Logic

For a direct quotation, the bank starts from the appropriate buying side of the market rate.

The customer is then given a rate after applying the bank's buying margin.

The basic relationship is:

TT Buying Rate = Applicable Interbank Buying Rate − Exchange Margin

Refer to the Formula Section for a detailed explanation, variables, and solved examples.

Why is the margin deducted?

Because the bank is buying foreign currency. A lower rupee rate means the bank pays slightly fewer rupees per unit of foreign currency than the relevant base market rate.

TT Selling Rate

The TT selling rate applies when the bank sells foreign currency in a clean outward transaction.

Examples include:

• outward remittance;

• foreign-currency transfer;

• issue of a foreign-currency demand draft or similar payment instrument where applicable;

• cancellation of certain earlier forex purchase contracts.

The bank starts with the appropriate selling side of the interbank rate.

TT Selling Rate Logic

TT Selling Rate = Applicable Interbank Selling Rate + Exchange Margin

Refer to the Formula Section for a detailed explanation, variables, and solved examples.

The margin is added because the bank is selling foreign currency to the customer.

Therefore, in a direct quotation:

TT Buying Rate < Base Market Rate < TT Selling Rate

This reflects the bank's buying and selling spread.

TT Buying vs TT Selling

Bill Buying Rate

The bill buying rate is relevant when a bank purchases, discounts or negotiates an export bill and pays rupees to the exporter before the foreign currency is actually realised.

This creates a time gap.

For example:

1. Exporter submits an eligible foreign-currency export bill.

2. Bank purchases or negotiates the bill.

3. Bank credits rupees to the exporter.

4. The foreign buyer pays later.

5. The bank's foreign-currency account is credited later.

Because the foreign exchange becomes available to the bank on a future date, the appropriate value of the currency for that period may have to be considered.

Current FEDAI rules provide that foreign-currency export bills purchased, discounted or negotiated are to be handled at the authorised dealer's current bill buying rate or contracted rate, as applicable, with relevant interest for normal transit and/or usance recovered as prescribed.

Bill Buying Rate and Forward Adjustment

In a CAIIB numerical question, the applicable rate may require adjustment for:

• normal transit period;

• usance period;

• applicable forward premium or discount;

• exchange margin.

Conceptually:

Bill Buying Rate = Applicable Buying Rate adjusted for relevant forward period − Applicable Exchange Margin

Refer to the Formula Section for a detailed explanation, variables, and solved examples.

The exact forward-rate selection depends on the information and delivery period given in the question.

Why Bill Buying Differs from TT Buying

The key difference is availability of foreign currency.

In TT buying, the funds are generally already available or available without the future realisation period associated with a purchased bill.

In bill buying, the bank gives rupees now but receives the corresponding foreign currency later.

Therefore, the relevant forward value becomes important.

[INFOGRAPHIC SUGGESTION]

Title: TT Buying vs Bill Buying Transaction Flow

Placement: After the section explaining why bill buying differs from TT buying

Format: Transaction-flow diagram

Content: Show TT buying as Foreign Currency Received → Bank → Rupees Paid to Customer. Show bill buying as Exporter Submits Bill → Bank Pays Rupees → Waiting/Usance Period → Foreign Buyer Pays → Bank Receives Foreign Currency.

Alt Text: Transaction-flow diagram comparing immediate foreign-currency availability in TT buying with delayed realisation in bill buying.

Bill Sent for Collection: Important Distinction

Suppose an exporter submits a foreign-currency bill to the bank for collection only.

The bank does not purchase the bill and does not immediately give the exporter the rupee value.

Instead:

1. The bill is sent for collection.

2. Payment is received from abroad.

3. The bank's Nostro account is credited.

4. The exporter is then paid the rupee equivalent.

At the point of conversion, the bank already has the foreign-currency proceeds.

Therefore, the applicable rate is normally the TT buying rate, not the bill buying rate.

This is a classic CAIIB trap.

Purchase vs Collection

Bill Selling Rate

The bill selling rate is associated with relevant documentary sale transactions, particularly payment or retirement of import bills.

For example, an Indian importer may receive documents through its bank under a documentary credit or collection arrangement and pay rupees to obtain the foreign currency required to settle the foreign liability.

The bank is:

• receiving INR; and

• selling foreign currency.

Therefore, it is a selling transaction.

Traditional CAIIB foreign-exchange arithmetic may give separate margins for TT selling and bill selling. Where the question provides both, apply them exactly according to the stated calculation convention.

A general exam relationship may be expressed as:

Bill Selling Rate = Applicable Selling Base Rate + Applicable Selling Margin(s)

Refer to the Formula Section for a detailed explanation, variables, and solved examples.

Do not memorise old fixed percentages as universal current regulatory margins. Exchange pricing is subject to the authorised dealer's applicable pricing framework, and a CAIIB numerical problem should provide the margins required for calculation.

TT Selling vs Bill Selling

Exchange Margin

An exchange margin is the adjustment made by a bank over the relevant base/interbank exchange rate while quoting a customer rate.

It contributes to the difference between the market rate and the merchant rate.

For a direct INR quotation, the broad logic is:

Bank Buys Foreign Currency

Margin works against the customer rate, so it is deducted.

Bank Sells Foreign Currency

Margin is added.

Thus:

Buying → Lower

Selling → Higher

This is safer to understand than merely memorising plus and minus signs.

Percentage Margin

If a question gives the exchange margin as a percentage, the margin amount is calculated on the relevant base rate as instructed.

Exchange Margin = Base Rate × Margin %

Refer to the Formula Section for a detailed explanation, variables, and solved examples.

After determining the margin:

• subtract it for an applicable buying rate;

• add it for an applicable selling rate.

Choosing the Correct Merchant Rate

Use the following decision sequence.

Step 1: Identify the Flow of Foreign Currency

Ask:

Is foreign currency coming to the bank or going from the bank?

Coming to bank → Buying transaction.

Going from bank → Selling transaction.

Step 2: Determine Whether It Is a TT or Bill Transaction

For buying:

• funds already available/clean receipt → TT buying;

• export bill purchased or negotiated before realisation → bill buying.

For selling:

• clean outward transfer → TT selling;

• relevant import documentary payment → bill selling.

Step 3: Select the Correct Interbank Side

For a direct quote:

• bank buys → buying/bid side;

• bank sells → selling/offer side.

Step 4: Consider the Time Period

If foreign currency will be realised in the future, as in an export bill purchased or negotiated, determine whether a forward adjustment is required based on the period given.

Step 5: Apply Exchange Margin

For a direct quotation:

• buying → deduct applicable margin;

• selling → add applicable margin.

Step 6: Apply Required Rounding

Use the rounding instruction given in the problem or the applicable quotation practice.

Do not round intermediate calculations unnecessarily.

[INFOGRAPHIC SUGGESTION]

Title: How to Select the Correct Merchant Forex Rate

Placement: After the section explaining the six-step rate-selection process

Format: Decision-tree infographic

Content: Start with “Is the bank buying or selling foreign currency?” Buying branches into “Funds available now?” leading to TT Buying or “Export bill purchased before realisation?” leading to Bill Buying. Selling branches into “Clean outward remittance?” leading to TT Selling or “Import documentary payment?” leading to Bill Selling.

Alt Text: Decision tree for selecting TT buying, bill buying, TT selling or bill selling rates in foreign-exchange transactions.

Practical Banking Applications

Inward Remittance

A customer receives USD from abroad.

The bank's Nostro account has been credited and the beneficiary must receive INR.

The bank has foreign currency and gives rupees.

Therefore:

Bank buys USD → TT buying rate

Outward Remittance

A customer needs USD for a permitted overseas payment.

The customer gives INR and the bank provides USD.

Therefore:

Bank sells USD → TT selling rate

Export Bill Purchased

An exporter submits an eligible USD export bill for purchase.

The bank gives rupees immediately, but USD will be realised later.

Therefore:

Bank buys USD for future realisation → Bill buying rate

The applicable future period may affect the rate.

Export Bill on Collection

An exporter submits a bill on collection basis.

The bank waits for the foreign currency to arrive before paying the exporter.

Once the Nostro account is credited:

TT buying rate generally applies for conversion.

Import Bill Retirement

An importer has to pay a USD import bill handled through the banking channel.

The customer pays rupees and the bank provides foreign currency for settlement.

This is a:

Bank selling transaction

Where the transaction is classified as a documentary bill transaction under the pricing arrangement used in the question, the bill selling rate applies.

Forward Premium or Discount in Bill Buying

This area is frequently confused.

When an export bill is purchased, the bank expects to realise foreign currency after the relevant transit/usance period.

Therefore, the applicable forward value may differ from today's spot value.

If the foreign currency is at a forward premium, its future rupee value is higher.

If it is at a forward discount, its future rupee value is lower.

The bill buying calculation must use the forward period and quotation specified in the problem.

Do not automatically:

• add every premium;

• subtract every discount;

• choose the longest maturity;

• use today's TT buying rate.

The applicable rate depends on the expected realisation/value date and the way the forward differentials are quoted.

Detailed forward-premium and forward-rate calculations belong to the separate forward-rate topic.

Merchant Rate vs Interbank Rate

A major exam mistake is to use the interbank rate directly when the problem specifically gives an exchange margin.

Bank Buying vs Bank Selling

CAIIB Exam Focus

1. Identify the Transaction Before Calculating

Do not start with arithmetic.

First classify the transaction as:

Buying or Selling

and then:

TT or Bill

Many wrong answers arise because candidates use the correct formula for the wrong transaction.

2. Nostro Already Credited

The phrase:

“Nostro account has already been credited”

is a strong clue for TT buying in a foreign-currency receipt.

The bank does not have to wait for future realisation.

3. Export Bill Purchased or Negotiated

This indicates that the bank pays the exporter before receiving foreign currency.

Think:

Bill buying

4. Export Bill Sent for Collection

Do not confuse collection with purchase.

If payment to the exporter is made only after proceeds are realised:

TT buying normally applies at the conversion stage.

5. Clean Outward Remittance

Customer needs foreign currency and pays INR.

Think:

TT selling

6. Import Documents

For a documentary import payment where the question specifies bill-rate treatment:

Bill selling

7. Buying Side vs Selling Side

For a direct quotation:

Bank buying → lower/bid side

Bank selling → higher/offer side

8. Exchange Margin

In a direct quotation:

Buying → subtract

Selling → add

9. Future Realisation

A purchased export bill may require a forward adjustment because foreign currency will be realised later.

10. Separate Exchange Rate and Interest

Do not confuse the rate adjustment with interest on export finance.

Current FEDAI rules separately provide for application of the bill buying/contracted rate and recovery of applicable interest for the normal transit and/or usance period.

Common Exam Traps

Trap 1: Looking from the Customer's Perspective

A customer says, “I am buying dollars.”

The examiner wants you to identify what the bank is doing.

If the bank is giving dollars, it is selling foreign currency.

Trap 2: Assuming Every Inward Transaction Uses Bill Buying

An inward remittance with funds already credited generally uses TT buying.

Bill buying is associated with the bank purchasing/negotiating an eligible bill before foreign-currency realisation.

Trap 3: Assuming Every Export Bill Uses Bill Buying

An export bill sent for collection is different from an export bill purchased.

After proceeds of a collection bill are received, TT buying normally applies to conversion.

Trap 4: Using Buying Side for Outward Remittance

An outward remittance requires the bank to sell foreign currency.

Use the applicable selling side, not the buying side.

Trap 5: Adding Margin to a Buying Rate

For a direct quotation, the bank's customer buying rate adjustment is normally downward.

Therefore:

Buying margin → deduct

Trap 6: Deducting Margin from a Selling Rate

For a direct quotation:

Selling margin → add

Trap 7: Ignoring the Forward Period in Bill Buying

If a bill will be realised later and forward information is provided, the spot rate alone may not be sufficient.

Trap 8: Treating Interest as Exchange Margin

Interest for the transit/usance period and exchange margin are different concepts.

Do not merge them unless the problem explicitly requires calculating both effects.

Trap 9: Using Old Standard Margin Percentages Automatically

Historical study material may show particular margin percentages.

Do not assume such percentages are universal current rates.

For CAIIB calculations, use the exchange margin specified in the question or applicable bank policy given in the case.

Trap 10: Confusing TT with Telegraph Technology

The term “TT rate” is traditional forex terminology. In examination questions, focus on the nature of the transaction—clean/immediate conversion versus relevant bill transaction—not on whether a modern electronic transfer is literally sent by telegraph.

Memory Techniques

“B-L, S-H”

For a direct quotation:

Bank Buys → Lower rate

Bank Sells → Higher rate

This helps identify the correct side of a two-way quotation.

“Buy Minus, Sell Plus”

For exchange margins in a direct quotation:

Buying → Minus

Selling → Plus

Use this only after correctly identifying the bank's position.

“Now = TT, Later = Bill” for Buying Transactions

As a quick memory aid:

Foreign currency available now → TT buying

Bank pays exporter now but foreign currency comes later → Bill buying

This is a memory technique, not a substitute for reading the transaction carefully.

Four-Rate Map

Remember:

Inward clean receipt → TT Buy

Export bill purchased → Bill Buy

Outward clean payment → TT Sell

Import documentary payment → Bill Sell

Once this classification is correct, most CAIIB merchant-rate calculations become much easier.