Open the reference-price section of the energy ministry's legal database and you will find a decree issued for most periods of the year. Its long title is formulaic: *Harga Mineral Logam Acuan dan Harga Batubara Acuan* — the reference price of metal minerals and the reference price of coal, for a stated period.
Two terms run through it. HMA — *Harga Mineral Acuan*, the reference price for a metal mineral — and HBA — *Harga Batubara Acuan*, the coal equivalent. The decree sets both, in two annexes.
An HMA is not the price at which a tonne changes hands. Under the decree, it is the basis for calculating the HPM, the *Harga Patokan Mineral* — the benchmark mineral price. The coal figure feeds the HPB, the benchmark coal price. It is those benchmarks, rather than the number on an invoice, that Indonesian state charges are measured against — a structure our explainer on [Indonesia mining royalties](/en/news/indonesia-mining-royalties) sets out in detail.
For a foreign investor the point is narrower and more practical. The HMA is a government number that changes on a known schedule, by a known method, and it anchors the economics of what you sell and what you pay. It is worth knowing exactly how it is made.
Who sets it, and under what authority
The decree we read in full is Ministerial Decree (Kepmen) No. 348.K/MB.01/MEM.B/2026 on the Reference Price of Metal Minerals and the Reference Price of Coal for the First Period of September 2026. It is dated 31 August 2026, takes effect on 1 September 2026, and is signed by the Minister of Energy and Mineral Resources, Bahlil Lahadalia.
Its own preamble names the instruments it is made under:
- Ministerial Regulation (Permen) No. 7 of 2017 on the procedure for setting the benchmark selling price of metal minerals and coal, as last amended by Permen No. 11 of 2020;
- Kepmen No. 268.K/MB.01/MEM.B/2025, the guidelines for setting the benchmark price for the sale of metal mineral and coal commodities, as amended by Kepmen No. 144.K/MB.01/MEM.B/2026;
- Government Regulation No. 96 of 2021, the implementing regulation of the mining law, as last amended by Government Regulation No. 39 of 2025; and
- the mining law itself, Law No. 4 of 2009, as last amended by Law No. 2 of 2025.
(For what that statute governs, see our explainer on the [Indonesia mining law](/en/news/indonesia-mining-law).)
The operative part is short. It sets the HMA for the period (the first *diktum*), sets the HBA for the period (the second), states that the HMA is used as the basis for calculating the HPM for that period (the third), states the same for the HBA and the HPB (the fourth), and brings the decree into force on 1 September 2026 (the fifth).
Which commodities it covers
The HMA annex lists 19 numbered lines. They are the metal minerals the government prices, grouped by which market the price is taken from:
- Base and industrial metals — nickel, cobalt, lead, zinc, aluminium and copper — priced from the London Metal Exchange (LME) cash seller and settlement price;
- Precious metals — gold and silver — priced from the London Bullion Market Association (LBMA);
- Tin — several grades of ingot (Pb 300, Pb 200, Pb 100, Pb 050 and "4NINE") priced from the Indonesia Commodity and Derivatives Exchange (ICDX) and the Jakarta Futures Exchange (JFX);
- Ore and concentrate grades — manganese (per Mn grade), iron ore (laterite, hematite and magnetite, per Fe grade), chromite (per Cr grade) and titanium concentrate (per TiO2 grade) — priced from Asian Metal.
Then there is the measurement window, which is the same for most of them. The LME, LBMA and Asian Metal figures are averaged from the 5th to the 25th of the month before the period the HPM applies to. Tin ingot is different again — it uses the ICDX and JFX settlement price on the day of sale — and so do the second gold and silver lines, which reference the LBMA Gold PM Fix at 15:00 and the LBMA Silver Fix on the day of sale.
For the first period of September 2026, the fixed values the decree states are these:
| # | Commodity | Basis | Unit | HMA |
|---|---|---|---|---|
| 1 | Nickel | LME cash seller and settlement, avg 5-25 | USD/dmt | 16,733.33 |
| 2 | Cobalt | LME, avg 5-25 | USD/dmt | 55,852.67 |
| 3 | Lead | LME, avg 5-25 | USD/dmt | 1,853.87 |
| 4 | Zinc | LME, avg 5-25 | USD/dmt | 3,849.17 |
| 5 | Aluminium | LME, avg 5-25 | USD/dmt | 3,253.30 |
| 6 | Copper | LME, avg 5-25 | USD/dmt | 14,358.53 |
| 7 | Gold (associated mineral) | LBMA, avg 5-25 | USD/troy oz | 4,421.49 |
| 8 | Silver (associated mineral) | LBMA, avg 5-25 | USD/troy oz | 64.38 |
The remaining lines — the five tin-ingot grades, the day-of-sale gold and silver lines, and the graded ores — are priced by reference to a market on the day of sale or by grade, and the decree states no single fixed number for them. The same decree also fixes the HBA, the coal reference price, in its second annex; for the first period of September 2026 the HBA is stated as USD120.87 per tonne for coal at 6,322 kcal/kg GAR.
What the series looks like
One period says little on its own. We read five decrees to see the movement in the metals that matter most to an offshore reader. All figures below are the first-period HMA in US dollars per dry metric tonne (USD/dmt).
| Metal | Oct 2025 | Nov 2025 | Jul 2026 | Aug 2026 | Sep 2026 |
|---|---|---|---|---|---|
| Nickel | 15,101.67 | 15,075.33 | 17,593.33 | 16,646.00 | 16,733.33 |
| Copper | 9,935.83 | 10,662.07 | 13,541.80 | 13,512.87 | 14,358.53 |
| Aluminium | 2,662.53 | 2,776.33 | 3,431.57 | 3,159.03 | 3,253.30 |
| Zinc | 2,939.37 | 3,148.70 | 3,534.60 | 3,588.80 | 3,849.17 |
| Lead | 1,954.20 | 1,959.33 | 1,949.87 | 1,839.20 | 1,853.87 |
| Cobalt | 33,307.67 | 42,283.33 | *(see note)* | 55,875.67 | 55,852.67 |
*Note: the July 2026 cobalt figure could not be read unambiguously from the scanned decree, so no value is printed for that cell.*
This is a sample, not a continuous series: we read the decrees for these five periods, and no others. Read as two windows — October to November 2025, and July to September 2026 — it shows copper and the light metals, aluminium and zinc, on a clear upward path across the year, nickel higher but with a dip between July and August, and lead essentially flat to lower. Cobalt is the outlier, well above its October 2025 level by September 2026.
Why it matters for a foreign investor
Five things follow from how the reference price is built.
- The price your charges reference is formulaic, not negotiated. Because the HMA comes from an average of exchange quotes over a fixed 5th-to-25th window, a producer can identify the window in advance. It also means the reference price lags spot by design — the period's benchmark is built from the previous month's trade.
- It is period-based, not annual. Every decree we read is issued for a month's *first period* (periode pertama) and takes effect on the first of that month. The reference price is refreshed within the year, not only once.
- For ores, grade decides your reference. Manganese, iron ore, chromite and titanium are priced per grade (Mn, Fe, Cr and TiO2 respectively), so the reference for your product depends on its grade rather than a single national number.
- Different commodities run on different clocks. LME, LBMA and Asian Metal are averaged over the 5th-to-25th window; tin ingot and the day-of-sale gold and silver lines use the market on the day the sale is booked.
- The benchmark is not the sale price — it is the anchor. Indonesian royalties and other state charges are expressed against a benchmark rather than an invoice, as our explainer on [Indonesia mining royalties](/en/news/indonesia-mining-royalties) sets out. For coal, the royalty bands key to the HBA, and the compensation formula for a producer that misses its domestic market obligation is also keyed to it — the obligation is covered in our explainer on the [Indonesia coal DMO](/en/news/indonesia-coal-dmo).
The practical read for a project model is to carry the benchmark, not the spot price you hope to realise, as the number the fiscal charge moves with. For how domestic sales volumes are approved — the variable that sits alongside price in the state's revenue arithmetic — see our explainer on [what the RKAB is](/en/news/what-is-rkab-indonesia).
Catatan Teramine
*This section is Teramine's editorial assessment, not a statement from any government body and not a recommendation.*
The first observation is about design. Averaging exchange quotes from the 5th to the 25th of the preceding month is a smoothing choice: it deliberately excludes the end of the month, when positions are rolled and prices are most volatile, and it hands a producer a window it can watch in real time. The reference price is therefore predictable in method even when it is not predictable in value.
The second is the dispersion. Taking the October 2025 first-period figure against September 2026, computed from the series above, the light metals and copper led: copper up about 44.5 per cent, zinc about 31.0 per cent and aluminium about 22.2 per cent, with nickel up about 10.8 per cent and cobalt up about 67.7 per cent, while lead was about 5.1 per cent lower. The spread is the interesting part. A benchmark that fixes copper and lead in one decree, three months apart in trend, tells an investor that "Indonesia's mineral reference price" is not a single story — the commodity decides it.
The third is a detail that repays reading carefully. The annex carries gold and silver twice: once as an *associated mineral* (mineral ikutan), a fixed figure for the period, and once as a metal priced at the LBMA fix on the day of sale. The two are not interchangeable, and a producer selling a by-product should know which line applies. We have printed only the fixed associated-mineral figures, because those are the ones stated as numbers.
The honest caveat is that a reference price is not a forecast and not a sale. It is an input the state computes and then applies. Its value to a reader is not what it says about the market but what it says about how the state will measure your project.
What we could not verify
- The HPM adjustment formula — how an HMA is converted into the Harga Patokan Mineral. That is set in the price-setting guideline Kepmen No. 268.K/MB.01/MEM.B/2025 (as amended by Kepmen No. 144.K/MB.01/MEM.B/2026), which the decree cites but which we did not read.
- Whether the mineral royalty is computed on the HPM, and by what formula. The decree states only that the HMA is the basis for the HPM; the charge itself sits under separate regulations.
- A second-period decree for any month, and any month outside the five we read. The series is a sample, not a continuous run.
- The July 2026 cobalt HMA, which did not read unambiguously from the scanned decree and is therefore not printed.
- Any specific company, project, reserve or sale referencing these prices. This article describes a price-setting instrument; it reports no transaction.
Sources
Every figure and every statement attributed to a rule in this article comes from the five official decrees below, each downloaded from the legal information database of the Ministry of Energy and Mineral Resources (JDIH ESDM). The five are scanned copies; each was read by rendering its pages and applying text recognition, and the values printed here are those that read consistently across passes.
- Kepmen No. 348.K/MB.01/MEM.B/2026, the reference price of metal minerals and coal for the first period of September 2026, dated 31 August 2026 (JDIH record: LL KESDM 2026:3 Hlm, Lamp:5 Hlm) — read for the whole decree: the preamble naming Permen 7/2017 as amended by Permen 11/2020, Kepmen 268.K/MB.01/MEM.B/2025 as amended by Kepmen 144.K/MB.01/MEM.B/2026, PP 96/2021 as amended by PP 39/2025, and Law 4/2009 as amended by Law 2/2025; the five diktums; Annex I, listing all 19 commodities with their measurement bases and the first-period values (nickel 16,733.33; cobalt 55,852.67; lead 1,853.87; zinc 3,849.17; aluminium 3,253.30; copper 14,358.53; gold as associated mineral 4,421.49; silver as associated mineral 64.38, in USD/dmt or USD per troy ounce); and Annex II, the HBA (coal) for the same period (USD120.87 per tonne at 6,322 kcal/kg GAR).
- Kepmen No. 312.K/MB.01/MEM.B/2026, first period of August 2026, dated 31 July 2026 — read for the first-period values (nickel 16,646.00; cobalt 55,875.67; lead 1,839.20; zinc 3,588.80; aluminium 3,159.03; copper 13,512.87; gold as associated mineral 4,072.12).
- Kepmen No. 274.K/MB.01/MEM.B/2026, first period of July 2026, dated 30 June 2026 — read for the first-period values (nickel 17,593.33; lead 1,949.87; zinc 3,534.60; aluminium 3,431.57; copper 13,541.80). Its cobalt line did not read unambiguously and no figure from it is used.
- Kepmen No. 348.K/MB.01/MEM.B/2025, first period of November 2025, dated 31 October 2025 — read for the first-period values (nickel 15,075.33; cobalt 42,283.33; lead 1,959.33; zinc 3,148.70; aluminium 2,776.33; copper 10,662.07; silver as associated mineral 50.37).
- Kepmen No. 326.K/MB.01/MEM.B/2025, first period of October 2025, dated 30 September 2025 — read for the first-period values (nickel 15,101.67; cobalt 33,307.67; lead 1,954.20; zinc 2,939.37; aluminium 2,662.53; copper 9,935.83).
For permit, document and compliance work against this framework, see our [permit services](/en/layanan-izin) page. For mining assets currently listed, see the [mining marketplace](/en/marketplace).
