TTM Rate Guide: Understanding Japanese Bank Exchange Rates

When filing expense reports for overseas business trips in Japan, you'll encounter three key exchange rate types: TTM, TTS, and TTB. Understanding these rates is essential for accurate and compliant expense reporting.

What is TTM?

TTM (Telegraphic Transfer Middle rate) is the mid-market exchange rate published daily by Japanese banks. It represents the midpoint between the buying and selling rates.

• Published by major banks (MUFG, Mizuho, SMBC) each business day around 10:00 AM JST
• Used as the standard reference rate for most business expense conversions
• Most accounting departments in Japan accept TTM as the default rate for expense reports

TTS vs TTM vs TTB

Rate

Full Name

Use Case

Spread

TTS	Telegraphic Transfer Selling	When you buy foreign currency (bank sells)	TTM + ~1%
TTM	Telegraphic Transfer Middle	Reference/mid-market rate	Baseline
TTB	Telegraphic Transfer Buying	When you sell foreign currency (bank buys)	TTM - ~1%

Which Rate Should You Use?

For most Japanese companies, the TTM rate on the transaction date is the standard for expense reports. However, some companies have specific policies:

1. TTM (most common): Used by the majority of Japanese companies
2. TTS: Some companies require TTS for purchases made abroad (conservative approach)
3. TTB: Rarely used for expenses; mainly for revenue received in foreign currency

Weekend and Holiday Handling

Banks don't publish rates on weekends or Japanese holidays. The standard practice is:

• Use the most recent business day's rate for weekend/holiday transactions
• Some companies allow the next business day's rate instead
• Always document which rate date you used and why

Pro Tips for Business Travelers

1. Screenshot the rate: Use Zenrate to capture rate evidence with timestamps
2. Be consistent: Use the same rate type (TTM/TTS/TTB) throughout your trip
3. Check your company policy: Some companies have specific bank preferences (e.g., MUFG only)
4. Save receipts: Digital photos with integrity hashes provide tamper-proof evidence

Use Zenrate for TTM Conversions

Zenrate's Business mode lets you select TTM, TTS, or TTB rates and generates rate evidence blocks that include the source, date, and rate type — ready for your expense report.