JPY to USD

Reference notes for JPY/USD

When you typically see JPY/USD

Japanese individuals and SMEs use this direction most often when paying for US-dollar-denominated services from Japan: AWS or Stripe monthly bills, US software subscriptions (Notion, Figma, Linear, JetBrains), US-based contractors invoiced via Wise or PayPal, US conference registrations. On the personal side, the same pair appears whenever a Japan resident wires dollars to a US brokerage to fund equities, or remits to a US-based family member. The remittance flow uses TTS (yen-to-foreign sale) at the originating bank. The third pattern is travel reimbursement: a Japanese employee on a US trip pays a hotel folio in USD, returns to Tokyo, and submits the receipt for translation to JPY at TTM on the trip date. This single use case probably generates the highest volume of jpy-to-usd lookups in Zenrate, because every line of a multi-day US trip needs its own rate.

How JPY/USD behaves in accounting

Mizuho publishes USD/JPY TTM, TTS, and TTB every Tokyo business day. This is the most-quoted pair in Japanese accounting and the one Mizuho's CSV format keys off. No cross-rating required. Volatility is moderate but the headline pair, so it moves on US payroll Fridays, Fed days, BOJ days, and Japanese fiscal-year transitions in March. For monthly-volume accounting (US SaaS subscriptions billed mid-month every month), prior-month-end or prior-month-average policies smooth this. For travel and one-off contractor payments, transaction date is the default. When the company's policy specifies TTS (for FX-purchase transactions) or TTB (for FX-sale transactions) instead of TTM, Zenrate reads the corresponding column from the Mizuho record. The three rates differ by Mizuho's published spread, typically 1 yen on either side of TTM.

Common conversion mistakes for JPY/USD

The timezone gap. A US transaction at 11pm Pacific on a Tuesday is already Wednesday in Tokyo. Using Tuesday's TTM when the receipt timestamp is Wednesday Tokyo time is technically wrong; most auditors accept it for trip expenses but flag it for treasury operations. Confusing the credit card statement rate with the transaction-date TTM. Visa and Mastercard publish a daily rate at settlement, and the card issuer adds 1.6%–3.5% on top. A USD swipe in San Francisco shows up on the cardholder's JCB statement at the network's settlement rate from two days later, plus markup. Reconciling that statement to Mizuho TTM on the trip date will always show a gap of 2–4% — that gap is the card markup, not a Zenrate calculation error. The fix is to use the credit-card policy for those entries and enter the statement rate directly. Third: applying TTM to a wire transfer that the bank actually executed at TTS. Banks transfer at TTS for outgoing USD wires (bank is selling dollars to the customer). Recording at TTM understates the cost by ~0.5%.

What Zenrate stores for JPY/USD

Live conversion uses exchangerate-api.com (USD-base, no cross-rate needed for USD-to-JPY since USD is the base). Cached for twelve hours in browser localStorage. Historical Mizuho TTM/TTS/TTB is the canonical Expense source for this pair and is the best-covered pair in the project's `bank_ttm_rates` ingestion. Dates more than a few years back may need to be fetched on demand via the edge function rather than served from cache. ECB JPY/USD is also retrievable via Frankfurter on any business day. US Treasury reporting rates publish JPY/USD quarterly; their granularity is too coarse for travel expenses but suitable for fiscal-year close. All six rate policies apply. Prior-month-average iterates through Mizuho's daily rates for the previous month — about 20 fetcher calls per request, which the cache absorbs in steady state.

These notes describe the rate sources actually implemented in @zenrate/core/rate-sources at the time of publication. Behavior may evolve; the source code is the ground truth.