How every figure here is produced

How a figure reaches the page

The step that matters is the fourth. A figure does not appear because it was imported; it appears because a person compared it with the original document and said so. Until then it sits in the database and no page will render it. That gate is enforced in the software, not by anyone remembering.

1. The source is recorded. The document is registered with its publishing institution, type, the period it covers, where it was obtained and when. Every one is listed on the sources page — 9 at present.
2. Figures are imported and attached to it. A figure cannot be stored without a source: the link is required at the database level, so there is no path by which an unattributed number enters. Validation runs during the import, and anything unrecognised stops it rather than being guessed.
3. The rows are held. They are in the database and invisible to the public.
4. A member of staff verifies the source. They compare the figures with the original document and mark it verified. The platform records who did it; that name is kept internal.
5. Only now is anything published. Charts, tables, downloads, the API and the headline figures all read the same place, so none of them can disagree with the others.

New figures are added when the Debt Management Office publishes them, which is quarterly.

How each chart is measured

These are the same statements printed on the charts themselves, so the two cannot drift apart.

Total public debt by quarter ₦ trillion

The total public debt figure published for each quarter, divided by one trillion for the axis. Nothing is smoothed, adjusted or interpolated: a quarter with no published figure is absent from the chart rather than estimated.

External and domestic debt by quarter ₦ trillion

The external and domestic figures as published, stacked. Neither is derived from the other or from the total, which is why in some quarters the two do not sum to the published total — where that happens neither figure is adjusted to close the gap.

Debt-to-GDP against borrowing limits % of GDP

The debt-to-GDP ratio recorded in the source, not recomputed here from debt and GDP, shown as a percentage. The two limit lines are the thresholds the source itself records. Quarters with no recorded ratio are left out.

External debt by creditor category US$ billion

Every published external holding for a year, summed by the category its creditor belongs to, in US dollars. Categories are named exactly as the Debt Management Office reports them rather than regrouped.

Largest external creditors, 2025 US$ billion

Individual creditors in the most recent year for which holdings are published, ranked by outstanding dollar debt, the largest eight shown. Creditors are not merged into parent institutions.

Domestic debt service — principal and interest by year ₦ trillion

Domestic debt service as published for each year, split into the principal and interest components recorded in the source. Only domestic service is counted; external service is not included.

What the software checks

Some charts carry a highlighted note. Those notes are produced by the import when it finds something in the government's own figures that a reader should be warned about. They are not editorial comment, and they are not written by hand — the conditions below are tested on every import.

• A borrowing limit that moves down. A self-imposed ceiling does not fall and rise again quarter to quarter. Where the recorded series does, the chart marks that line indicative rather than drawing the zig-zag as though it were policy.
• A ratio falling while debt rises. If debt-to-GDP drops by 10 percentage points or more while the debt itself grew, the denominator changed. The chart says so, rather than letting the fall read as an improvement.
• A category counted twice. Where the source lists something both as a creditor category and as a creditor inside another category, both are shown separately and the duplication is stated, rather than silently merged.
• Components that do not sum to the total. Where external plus domestic does not equal the published total, neither figure is adjusted to close the gap. The discrepancy is reported as the source's own.

How current a figure is

Debt figures are normally published a quarter or two in arrears, so age is measured against the real publication lag rather than the calendar. Figures carry a marker when they fall behind it.

• Current — retrieved within 180 days.
• Ageing — more than 180 days old.
• Stale — more than 365 days old; treat with caution.

What is not settled

These are open. They are listed because a methodology page that only described the parts we have worked out would be a worse document than one that says where the gaps are.

• Which borrowing limit applies to which period. The country-specific threshold in our source moves up and down over the period covered. Until the Debt Management Office confirms the series, that line is indicative and we make no public claim about limits being breached. Settled by: written confirmation of the threshold series from the DMO.
• The change in the GDP denominator. The sharp fall in debt-to-GDP while debt rose points to a rebasing. We have not confirmed the rebasing or its date, so the break in the series is flagged but not labelled. Settled by: confirmation of the rebasing and its effective date.
• The quarters that do not add up. In several quarters, external plus domestic debt does not equal the published total. We report the discrepancy rather than adjusting either figure, and we have not published it as a finding because we cannot yet explain it. Settled by: an explanation from the DMO, or a reconciliation we can defend.

Every document behind these figures is listed on the sources page. Every chart publishes its own numbers as a table and as CSV and JSON on the data page.