Every word these documents use in a sense of their own: the customs vocabulary, Burundi's charges, the tariff data model, the parts of the calculator and the way the work runs. Type in the box to filter, in English or French; accents do not matter; each entry has its own link, and / jumps to the box. A word defined here is used in this sense everywhere else.
The customs management system UNCTAD builds and supplies to about a hundred countries, where it registers declarations and assesses duties. Also called SYDONIA in French-speaking countries. Burundi and Rwanda both run it. See also: ASYCUDA tariff API.
The web service placed in front of ASYCUDA that answers product searches, serves reference tables and computes an estimate for a shipment (POST /api/v1/estimate). Of the customs systems checked on 29-09-2026, it is the only one that computes an estimate on request. Its only written contract is RRA's OpenAPI file, accurate for 21 of its 23 endpoints.
Office Burundais des Recettes: Burundi's revenue authority, which runs customs and ASYCUDA in Burundi. Owner of the tariff service the prototype and eRegulations v7 call.
Rwanda Revenue Authority: Rwanda's revenue authority, which runs customs and ASYCUDA in Rwanda.
East African Community: Burundi, Kenya, Rwanda, Tanzania, Uganda and other members, joined in a customs union with one common external tariff.
French: tarif extérieur commun (TEC). The customs duty every EAC member applies to goods from outside the community, in four bands: 0, 10, 25 and 35 %, in the 2022 version in force since 01-07-2022. Published as a PDF gazette; no machine-readable copy was found. In Burundi it is the DDI.
French: sursis d'application. An EAC decision letting one member apply, for a set period, a rate other than the common external tariff's on named products. Gazetted country by country, so the duty on the same product can differ between EAC members.
French: remise de droits. An EAC scheme that lowers or removes the duty on named goods for named users or purposes, country by country.
Common Market for Eastern and Southern Africa, a trade area Burundi and Rwanda belong to besides the EAC. Its preferences lower the duty on goods from some members, such as the 10 % reduction for Ethiopia raised at the OBR meeting of 24-09-2026.
Also: preferential treatment, trade agreement; French: traitement préférentiel, accord commercial. A lower duty granted to goods of a given origin under an agreement. In ASYCUDA, the preferences table lists the agreements and country-preferences the countries each allows. Nothing is applied by default: the importer picks one, and only those allowed for the chosen origin are offered.
French: origine. The country where the goods were produced, which decides the preferences they may claim and, in Burundi, whether the RIR is due. Not the country they were shipped from.
French: Système harmonisé (SH). The World Customs Organization's classification of goods, six digits long, revised every five years. Countries add digits of their own: Burundi's commodity codes have eleven.
Also: HS code, tariff line; French: code SH, ligne tarifaire. The code that identifies a product in a country's tariff, such as 10062000000 for husked rice in Burundi. OBR's catalogue holds 6 278 of them. The calculator does not classify goods: the importer picks the code.
The whole tree of commodity codes, from HS chapters down to the national lines, with their descriptions.
A commodity code at the lowest level of the nomenclature, the only kind a declaration may carry.
French: déclaration. The document an importer lodges with customs to clear goods. Customs assesses the duties on it; that assessment is binding. The calculator never produces one.
Also: IM, EX; French: type de déclaration. Whether the goods are imported, exported or in transit, with its procedure. OBR's types table offers more types than its service computes; exports returned server errors until OBR opened them.
Also: CPC, extended procedure, national procedure; French: régime douanier. The regime under which goods are declared, such as release for home use, which decides the charges that apply.
Also: Incoterms, tod; French: conditions de livraison. The international terms that say which costs the price includes: CIF, FOB, EXW and others. OBR's tod table lists nineteen.
Cost, insurance and freight: the price of the goods plus the insurance and the freight to the point of entry. The basis of the customs value in the EAC.
Free on board: the price of the goods loaded at the port of departure, without international freight or insurance. The basis of the customs value in the United States, among others.
French: valeur en douane. The value on which duties are assessed. In Burundi: invoice, plus external freight, insurance and other costs, minus deductions, measured on 28-08-2026. Internal freight is not part of it.
French: fret extérieur. Freight up to the point of entry into the EAC. Part of the customs value.
French: fret intérieur. Freight inside the EAC up to Burundi, for example from Mombasa to Bujumbura. Outside the customs value, but inside the base of the RAD, the TSR and VAT. OBR asked on 24-09-2026 that it be a field of its own.
French: liquidation. The duties customs computes on a lodged declaration: the only binding figure. See also: estimate.
French: estimation, simulation. What the calculator shows: the duties a shipment would pay, before any declaration. Never binding, whoever computes it.
French: taux de change. The rate customs uses to convert a foreign currency into the local one, published by customs, usually weekly. When customs computes, the calculator shows customs' rate to six decimals and consults no other.
French: unité supplémentaire. A second quantity some tariff lines require besides weight, such as litres or number of items. Specific rates are charged on it.
A value a tariff line needs besides the usual fields, such as a vehicle's cylinder capacity for HS headings 8701 to 8705, 8709 and 8716 in eRegulations v7.
Droit de douane à l'importation: import customs duty. The only charge set at EAC level, through the common external tariff; OBR collects it.
Taxe sur la valeur ajoutée: value added tax, 18 % standard, 10 % on foodstuffs listed by ministerial ordinance, 0 %. Its base is the customs value plus transport to the first destination in Burundi plus every other charge, minus the PFR (VAT law of 2020, art. 18 and 19).
Redevance administrative: administrative fee, 1 % of the customs value delivered to Burundi (finance law 2026/27, art. 73).
Financement des infrastructures publiques: a 1.5 % charge on the customs value of all imports, with exemptions including listed foodstuffs (finance law 2026/27, art. 136).
Taxe or redevance de sûreté: security levy, 2 % (finance law 2026/27, art. 135). It went from 1.15 % to 2 % in December 2025, which is why rates are dated from any day, not only from July.
Prélèvement forfaitaire: a 3 % withholding on imports for resale, an advance on income tax the importer can credit later (finance law 2026/27, art. 75). Excluded from the VAT base.
Redevance informatique: IT fee, 0.25 % of the customs value on each declaration (finance law 2026/27, art. 110).
Redevance d'intégration régionale: regional integration fee, 2 %, new in 2026/27, due only on goods whose origin is outside the African Union (finance law 2026/27, art. 137). Known OBR defect: charged whatever the origin.
The two parts of the consumption tax on wines and spirits: TBL ad valorem (80 % for wines other than sparkling), TSV specific per litre (130 BIF/L for other wines) (finance law 2026/27, art. 90).
A 5 US dollar form fee, charged flat and converted at customs' rate. Its legal basis was not found in the finance laws searched.
Also: loi de finances. Burundi's yearly budget law, in force from 1 July, which sets every charge except the DDI and the basic VAT rates. The law in force is Loi n°1/10 du 30 juin 2026.
The European Union's integrated tariff, and the model the calculator's data follows: a nomenclature, and measures attached to it. The United Kingdom and Switzerland use the same model. It is the de facto model; there is no formal standard.
A rule that one tax applies to some commodity codes, from some origins, under some procedure, between two dates, under a legal act. Attached to a node of the nomenclature, with or without its descendants.
Also: duty component. One term of a measure's rate. Ad valorem (a percentage of a base), specific (an amount per unit) or several joined: plus, minus, MAX (a ceiling: the smaller value wins) and MIN (a floor: the larger value wins).
A rate expressed as a percentage of a value, such as 25 % of the customs value.
A rate expressed as an amount per unit, such as 130 BIF per litre.
A rate made of several components, such as "25 % or USD 200 per tonne, whichever is higher".
An amount due whatever the value, such as the DMC's 5 dollars. OBR returns it in the same field as a percentage; the calculator tells them apart by customs' arithmetic: if base × rate equals the amount, it is a percentage.
Part of a measure that makes it depend on a certificate, a document or a threshold of value or quantity.
A kind of charge, such as DDI or TVA, with its calculation order, its base expression, its currency and its rounding.
The sum a tax type is charged on, written in a closed language of named quantities and plus and minus signs, such as customs value + DDI + excise. It cannot contain code.
The order in which taxes are computed, so that a tax whose base includes another is computed after it.
A dated, complete copy of a country's tariff, with its source, legal reference, checksum and status: draft, validated, published, superseded. The engine only reads published versions.
A piece of the calculator that turns one kind of source into a draft tariff version: a spreadsheet or CSV schedule, manual entry, a PDF gazette, an API.
A rate written as words in a source, such as "Free (A, AU…)" or "25% or USD 200/t". The CSV connector reads it into components.
One country's list of its data sources: for each, the authority, the document or address, the format, how often it changes, the connector and who checks it.
One real shipment with the customs authority's answer to it, tax by tax, kept as a test. The engine must match it after rounding D12, except for taxes named in the register of known defects. At least twenty before step 7.2 D25.
The list of the customs service's answers known to be wrong and reported to it, such as the RIR charged whatever the origin. A tax named there is left out of the golden-case comparison, never copied.
A source that collects many countries' tariffs: ITC's Market Access Map, UNCTAD TRAINS through the World Bank's WITS, the WTO's tariff data. It may seed a first version but never replaces a national source; none carries national levies, and TRAINS stops at 2021 for Burundi.
The World Customs Organization's model of a declaration's data. Its duty-tax-fee element suits the calculator's result lines: base, rate, amount.
The product: a public page where an importer picks a product, describes a shipment and reads every duty and tax it would pay, with the rate, base and legal source of each. Runs on its own or embedded in a portal.
One running copy of the calculator for one country, with its own database, settings and address D20.
The calculator's own API: product search, product details, reference tables, estimate. Exact decimal amounts, a currency for each amount, the calculator's own codes. It is the only shape the page knows; providers never have to change for it D23.
What answers the contract for an installation. Three exist or are planned: the ASYCUDA provider, the computing provider, and the rwandatrade.rw provider for Rwanda D21. Chosen on the installation's administration page D20.
The file that translates between the contract and one provider's own shapes and codes. A provider's vocabulary never goes past its adapter.
The provider that sends the estimate to a customs service's ASYCUDA tariff API and shows its answer, correcting nothing. A port of v7's TariffsBO.
The provider that computes the estimate itself, from a published tariff version, with the engine. Its figures are always indicative.
The part of the computing provider that turns a shipment and a tariff version into charges: customs value, choice of measures, components, then each tax in order on its base, then rounding. Pure functions, no database.
The explanation attached to each result line: the measure used, its legal act, the base, the rate and the formula.
Marked on every figure the calculator computes itself, as opposed to a figure the customs service returns.
Running both providers for one country: the importer sees the authoritative answer, and every difference with the other is logged, tax by tax.
A provider that invents answers, for demonstrations and tests only. A live installation refuses to start with one, after another country's data was once shown as Burundi's (06-08-2026).
The lists the form needs, served by the provider: countries, currencies, units, packages, procedures, delivery terms, preferences, exchange rates. Eleven in ASYCUDA's API.
Placing the calculator inside another site: an iframe of the country's embedded page, or one script tag that inserts it. Only the sites listed for the country may do so D9.
The instruction a page sends to browsers to say which sites may display it in a frame. The calculator's embedded page lists the country's allowed sites.
Cross-origin resource sharing: the rule by which a browser lets a page on one site call another site's API. The prototype allowed every site; the calculator allows its own pages and the listed sites.
Refusing a caller who sends too many requests too fast. v7 counts per address taken from a header any client can forge; the calculator trusts only its own proxy's.
The two credentials the ASYCUDA tariff API reads, as request headers only. The key never reaches the browser: the server adds it.
The certificate linking a server's own to a trusted authority. OBR's server does not send it; the calculator carries it rather than switching verification off.
The first calculator, unctad-ai/tariff-calculator, 04-08 to 25-09-2026: plain pages for Burundi and Rwanda and a 184-line relay. The source of the measured facts and of the rule that customs' answer is never corrected.
The prototype's small server between the browser and customs: it holds the key, adds CORS headers and allows nine routes only.
The .NET 8 version of eRegulations (repositories eRegulations-4.0-Public and -Admin, released as core-v7.x), which carries its own tariff calculator since 04-09-2026. This project does not touch it while the calculator is built D19.
The class in eRegulations v7 that talks to the ASYCUDA tariff API: 447 lines, 3 commodity endpoints, 11 reference tables, the estimate. The ASYCUDA provider is its port.
The SQL Server table in which eRegulations v7 keeps ASYCUDA's reference tables, 7 days by default.
Rwanda's trade portal, whose tariff API (/api/Tariffs/*) answers estimates for Rwanda. The prototype calls it; so will pilot 2 D21.
UNCTAD's template for services built by agents (Next.js, Prisma, Postgres), cut from ePhyto on 17-09-2026. The calculator starts from it at step 7 D6, D18.
The template's rule that every value says where it is changed: 1 an administration screen, 2 a data file, 3 a rule or parameter, 4 code. Try them in that order.
The template's rule for outside systems (M5): an interface in the platform's words, a stand-in, a switch, a failure policy, what the screen says while it is down, a test, and who to call.
Also: template:pull, template:drift. The template's commands to bring its later fixes into a product made from it, and to see what has moved.
Whoever decides for the project. Every role in these documents is written this way, never with a name D8.
One of the seven stages of the work, each ending on something achieved: 1 concept note, 2 short specifications, 3 mockups, 4 detailed specifications, 5 detailed mockups, 6 build phases, 7 the tool.
One of the four passages inside a step: draft, first agreement, review, final agreement. The final agreement ends the step; nothing is drawn or built before it.
Step 1's document: what the calculator is, how it is built, the pilots, the risks and the decisions.
Step 2's document, one per module, at most 450 words: definition and examples, functions, related documents, rules, decisions needed, sources.
One of the eleven parts step 2 specifies: 0 public page, 1 product search and nomenclature, 2 estimate form, 3 result and its evidence, 4 ASYCUDA provider, 5 engine, 6 tariff data and ingestion, 7 administration, 8 embedding, 9 health and usage, 10 technical.
A review by agents with no stake in the document, looking for what is wrong, missing or contradictory. Each finding is numbered, graded blocker, major or minor, and followed to what became of it.
A choice the analyst made, numbered D1, D2… in the decision log, dated, with where it is recorded. Never renumbered; overturned only by a later decision naming it.
A choice waiting for the analyst, numbered ?1, ?2…, each with its options and a recommendation.
A country run end to end to prove the calculator. Pilot 1 is Burundi, computed and compared with OBR; pilot 2 is Rwanda D5, D13.