Guaranteed Rate vs the Rate You Actually Get

What a "guaranteed rate" actually guarantees

A guaranteed rate is an exchange rate a provider locks in for a specific period of time when you set up a transfer, to protect you from the market moving against you before your money arrives. It is not a fixed price for the transfer itself — it's a time-limited hold on today's rate.

Wise's own help centre describes it this way: "A guaranteed rate is an exchange rate that Wise locks for a specific period of time. We offer this for most transfers to protect you from market fluctuations. If currency markets are especially volatile, we might not be able to offer a guarantee" (Wise Help Centre, "What's a guaranteed rate?", fetched September 2026). If the market is unusually volatile at the moment you set up a transfer, the rate lock may not be offered at all, and you're shown a live-rate transfer instead.

How long the lock actually lasts

This is the detail most people get wrong: a guaranteed rate is not held for a fixed 24 hours across the board. Per Wise's help centre (fetched September 2026), the lock duration "ranges from 2–48 hours depending on the currency you're sending," and the exact deadline is shown to you at setup, converted to your device's local time zone.

How the clock starts also depends on payment method. If you're paying with a connected bank account, the rate locks the moment you authorise the payment. For any other payment method, it locks only once the full amount for your transfer has actually reached the provider — not when you click confirm.

What quietly voids the lock before the clock runs out

Three things can end a rate guarantee earlier than the stated window, per Wise's own help centre:

1. Sending only part of the money. If you fund a transfer in instalments, the guarantee doesn't apply — you have to complete the full amount, or send the remainder before the original deadline, to keep the locked rate.
2. Taking too long at setup. If more than 30 minutes passes on any single step while you're setting up the transfer, the quoted rate refreshes to whatever the market is doing at that moment.
3. A sharp market move. Wise states it sets an internal limit of 5% — if the mid-market rate drops by 5% or more before your funds are received, the transfer is automatically cancelled and refunded rather than honoured at the old rate.

None of these are unique to one provider; a locked rate is, by definition, conditional on funding arriving on time and in full.

Weekends, holidays, and why your deadline looks longer than it feels

Currency markets close on Friday evening (US time) and reopen Monday morning (in the Asia-Pacific session), and providers generally don't count that closed window against your deadline. Wise's example: a transfer set up Friday at 5:00pm with a 48-hour lock is guaranteed until Tuesday at 5:00pm, because the weekend doesn't count. If you set up a transfer just before a market close, you'll be given the last available rate from before the close.

The practical effect is that a "48-hour" guarantee on a large transfer set up on a Thursday or Friday can genuinely stretch into the following week — useful if you're waiting on a bank transfer to clear, but easy to misjudge if you assume the clock runs on calendar hours.

What happens once the window closes

If your money reaches the provider after the guarantee has expired, the transfer isn't cancelled outright — it's converted at whatever the live mid-market rate is at the moment the funds actually arrive, not the rate you were originally shown. Wise's own example: a rate expiring at 2:00pm, with funds arriving at 4:00pm, is converted using the live rate active at 4:00pm.

This is the single biggest reason someone ends up with a noticeably different amount than they expected days earlier: not a fee they weren't told about, but a rate lock that had already lapsed by the time their bank transfer actually cleared.

When a short guarantee window genuinely isn't enough

A 2–48 hour lock suits a transfer you can fund immediately. It doesn't suit a payment tied to a date that's weeks or months away — a property settlement, a visa instalment, or a large sum you won't have available until an overseas asset sells.

For that longer horizon, a forward contract is a different mechanism, not a longer version of the same guarantee. OFX's Product Disclosure Statement (revised 15 July 2026, v2.7) describes a Forward Contract as an arrangement that lets you "transfer money at some time (up to 12 months) in the future at an exchange rate that you agree now... so that you know what the exchange rate will be on the agreed settlement date," and it explicitly names being used by individuals "when they are for example migrating or buying a property overseas." The trade-off is stated in the same document: locking in a forward rate "also means that you may forego any future exchange rate movement that is in your favour." It's a mechanism for de-risking a distant, known date — not a way to avoid the trade-off a short guarantee already involves.

If you were charged a worse rate than you were quoted

Before assuming something has gone wrong, check three things: what the original guarantee window was (shown on your transfer confirmation at setup), when your funds actually reached the provider, and whether you funded the transfer in full or in instalments. In most cases the answer is one of the mechanics above, not a billing error.

If the timing and funding both look right and the rate still doesn't match what you were quoted within the stated window, that's a legitimate case to raise with the provider's support team directly, quoting the original quote reference and the time your payment was sent.

Is a guaranteed rate the same as a fixed price for my transfer?

No — it's a time-limited hold on today's exchange rate, not a fixed total cost. If your funds arrive within the guarantee window and in full, you get the locked rate; outside that window, the live rate applies instead.

How long is a rate usually guaranteed for?

It varies by provider and currency. Wise states its guarantee runs 2 to 48 hours depending on the currency being sent, shown to you at the point of setup — it is not a flat 24 hours across every transfer.

Why did my transfer get cancelled instead of just re-priced?

Some providers automatically cancel and refund a transfer if the market moves sharply before your funds arrive — Wise states an internal 5% move as its trigger — rather than completing it at a rate that's moved significantly against the quoted one.

Do weekends count against my rate-lock deadline?

Generally no. Providers typically don't count weekend or public-holiday hours (based on the currency's market) toward the guarantee window, so a lock set up on a Friday can effectively extend into the following week.

What should I use if I need a rate held for months, not hours?

A short rate guarantee isn't designed for that. A forward contract — offered by specialist FX providers, not app-based guarantees — locks a rate for a future settlement date, in OFX's case up to 12 months ahead, at the cost of giving up any favourable rate movement in the meantime.