How we handle rate data

We never merge these into one number, and we never call any of them “the” rate. Each one is labelled where it appears.

“Buy” and “sell” on this site are always about you. If you’re buying US dollars, you pay naira and the BDC sells to you — a lower naira rate is better for you. If you’re selling dollars, the BDC buys from you — a higher naira rate is better for you. Rates are always naira per one unit of the other currency (“per $1”).

The one exception is the CBN’s own rates. There, “buying” and “selling” are the CBN’s side, so we always write CBN buying and CBN selling — see below.

Every business day the Central Bank of Nigeria publishes three rates for each currency. We show all three, labelled the same way everywhere:

CBN central

The middle of the three. It’s the one we chart and alert on, and the one the calculator uses unless you choose another.

CBN buying

The CBN’s published buying rate for the currency, a little under central.

CBN selling

The CBN’s published selling rate for the currency, a little over central.

CBN buying and CBN selling sit a little either side of central. They are the CBN’s own rates for the official market, where banks trade — not what a licensed bureau de change (BDC) will charge you or pay you. None of the three is a price you can get.

We show each figure to 2 decimal places. The CBN publishes 4; each currency’s page has the exact figures, and the calculator works with them. Charts, rate alerts, the “Which rate is which?” table and our checks on BDCs’ posted rates use CBN central.

The CBN also publishes a separate rate for the Nigerian Foreign Exchange Market (NFEM) — an average of the day’s trades between banks, weighted by size — which it calls the official exchange rate for the day. We don’t import that figure. On the one day we have compared (Friday 25 September 2026), the NFEM closing rate reported in the press for the US dollar, ₦1,329.51, was the same as CBN selling. We haven’t confirmed that this holds every day, so we never present one as the other.

The CBN’s rates — buying, central and selling — come from the Central Bank of Nigeria’s published exchange rates. We fetch them a few times a day, keep every day’s figures with the date they are for and the time we received them, and never change what the CBN published. If the CBN corrects a past value, we record the correction.

If the CBN’s feed hasn’t delivered a business day, a member of our team may copy that day’s figures from the CBN’s website, cbn.gov.ng. Those figures are labelled “Entered by Trust Aboki staff from CBN’s website on …”, next to the rate and in the table of recent days, and each currency shows the date its own figures are for. When the feed delivers that day, its figures replace the copied ones.

Posted rates are entered by licensed BDCs themselves. Only a BDC whose CBN licence we have checked against the CBN’s published list, and whose account is in good standing, can post. Each BDC can post one buying and one selling rate per currency, for the currencies it says it deals in.

Recent quotes come from offers licensed BDCs sent to customers on Trust Aboki. We publish them only as summaries, never as anyone’s individual offer.

We never publish “black market” or “parallel” rates, rates copied from other websites, or rates from unlicensed dealers. They can’t be checked, and dealing with unlicensed dealers is an offence.

Every rate shows its date or time. We work out freshness from the data’s own timestamp, never from when a page was last refreshed, and the rules depend on the source:

• CBN rates: published after each business day. Friday’s rates on Monday are current. One business day behind, we say newer ones may be due; two or more behind, we say they are out of date and show their real date. Public holidays can cause a gap.
• Posted rates: a BDC chooses how long a rate stands — 1, 2, 4, 8, 12 hours. For the first 2 hours we show when it was posted; after that we add “may have changed since”. When its time ends it disappears from every page, even one that was already open.
• Recent quotes: worked out every 15 minutes from offers made in the last 6 hours.

Nothing on Trust Aboki is labelled “live”: none of these sources updates by the second.

CBN rates that move far more than usual from one day to the next are shown with a note while our team double-checks them, and don’t trigger rate alerts until they are confirmed. A value the CBN clearly published by mistake is hidden from every page and chart, and kept for our records.

CBN rates our team enters must be for a business day in the last 30 days that the feed hasn’t delivered, with CBN buying no higher than central and CBN selling no lower. A figure more than 10% from the previous CBN central rate is refused; a move that large should come from the feed. We record who entered it and the CBN page it came from.

Posted rates are refused if they are more than 30% away from the CBN central rate (almost always a typo), or if a BDC’s selling rate is below its own buying rate. A rate is held for our team to look at before it shows if it is more than 10% from CBN central, more than 5% away from that BDC’s last rate within a day, has no CBN rate to compare with, or comes within 24 hours of our team taking one of its rates down. These thresholds are our defaults; we may adjust them, and every change is recorded.

A BDC that is suspended, restricted, away or whose licence check has lapsed disappears from the posted rates immediately — we check on every page view, not once a day.

For posted rates we show the best rate for you, the least favourable one and how many BDCs have posted — and every one of those numbers belongs to a named BDC. We don’t average posted rates: an average of a few BDCs’ prices would look like a market rate nobody is actually offering.

For recent quotes we take each BDC’s middle quote first, so a BDC answering many requests counts once, then the middle of those (the median) and the middle half. We show a figure only with at least 3 quotes from 3 different BDCs; otherwise we say there aren’t enough.

“Today at a glance” sentences are put together from these same numbers by fixed rules. No one writes them by hand and nothing is predicted.

By city: a city’s posted rates come from BDCs that serve that city. A BDC serving several cities posts one rate for all of them, so it appears in each.

Charts show real CBN values only, one per business day. A stretch with no published rate breaks the line rather than joining the dots. The scale starts at the period’s low, not at zero, and the high and low are written next to the chart. A range (say, one year) is offered only when we hold data for all of it. Every chart has a written summary, and recent days are in a table.

Changes always say what they compare with: “+0.40% since Thu, 1 Oct”. If there is no value to compare with, we say so instead of guessing.

The calculator uses exact decimal arithmetic. Foreign currency to naira is rounded to the nearest kobo, then shown to the nearest naira. Naira to foreign currency is rounded down to the cent, so it never says your naira buys more than it does. It uses CBN central unless you choose CBN buying or CBN selling, and works with the exact figure the CBN published. Each result shows the rate it used and the sum. A calculation is not an offer.

An alert says exactly what it watched — “USD/NGN CBN central rate rises above ₦1,500” or “best rate posted by a licensed BDC serving Lagos for customers buying USD falls below ₦1,450” — never just “USD is now ₦1,500”. It fires when the rate crosses your level, not every time we check, and at most once a day; it can end on a date you choose. An alert on the CBN central rate never fires on figures our team entered; it waits for the CBN’s feed.

A city gets its own page of licensed BDCs (linked from the BDC directory) only while at least one listed BDC serves it. A BDC serves a city when it lists the city, an area in it, or the whole state as where it serves customers; we never guess it from a branch address. The counts on a city page are of listed BDCs (licence checked and current, trading on Trust Aboki), and the currencies are what those BDCs tell us they buy and sell, not rates. We don’t make up a local rate from a national one: a city’s rates are the ones its BDCs posted.

The figures on these pages come from Trust Aboki’s public data API, which answers with the same rates, sources, times and freshness you see here. It is read-only and needs no account. Its contract is published at /api/v1/openapi.json.

• A posted rate is the BDC’s own statement. We check who the BDC is, not every transaction; the rate you get is the one in their offer to you.
• Rates differ with the amount, the branch, the time of day and the documents you bring.
• We have one official source (the CBN). We don’t cover every currency or city.
• Public holidays aren’t built into the CBN freshness rules yet.

Trust Aboki never holds, moves or exchanges money. When you choose an offer, you exchange at the BDC’s branch and pay the BDC directly.