Claude Invoices & Billing: API Key Setup, First Call

Claude Pro/Max and Console API each have their own billing pages where you can look up invoices and receipts. Whether a Taiwan eGUI is also issued depends on how that transaction is taxed and on the purchase channel; entering a Tax/VAT ID does not guarantee an eGUI. Official documentation checked: 2026-09-24. Claude Pro/Max Tax/VAT ID guide.

Claude API Key Setup and Your First Anthropic API Call

An Anthropic API key is created in Claude Console, and then you send requests through the Messages API; API usage is billed by model and tokens. The Claude App's Pro/Max subscription and the API Console are separate billing entry points. Below, we first create a key and test a request, then go on to the original Taiwan procurement and billing notes.

Applying for a Claude API key in the official Console

1. Log in to Claude Console and open Settings → API Keys.
2. Click Create Key, and set a name, an expiration date and the account or workspace it belongs to.
3. Put the key in the ANTHROPIC_API_KEY environment variable. Do not write it into web front-end code, a repository or public logs.

Anthropic official Authentication documentation checked: 2026-09-24: Creating and using API keys.

First request: Anthropic Messages API

This example calls the official POST https://api.anthropic.com/v1/messages; use the key created in the Console.

export ANTHROPIC_API_KEY="your Anthropic API key"
curl https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{"model":"claude-sonnet-5","max_tokens":128,"messages":[{"role":"user","content":"Explain in one sentence, in Traditional Chinese, what an API key is."}]}'

OpenAI-compatible API example

If your application uses the OpenAI Chat Completions format, you can set the base URL to https://api.bazaarlink.ai/v1 and use a BazaarLink key. This is a general application API example; for how to set Claude Code's custom environment variables, see the CLI notes later in this article.

export BAZAARLINK_API_KEY="your BazaarLink key"
curl https://api.bazaarlink.ai/v1/chat/completions \
  -H "Authorization: Bearer $BAZAARLINK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-sonnet-5","messages":[{"role":"user","content":"Explain in one sentence, in Traditional Chinese, what an API key is."}]}'

Claude API pricing and available models

As of 2026-09-24, the official Anthropic price list shows Claude Sonnet 5 at US$2 / US$10 per million input / output tokens, and Claude Sonnet 4.6 at US$3 / US$15. Cache writes and reads have separate unit prices. BazaarLink's current catalog also lists Sonnet 5 at US$2 / US$10. Actual bills are calculated by model, token type and feature. You can check the Anthropic official pricing, the Claude Sonnet 5 model page, the Claude Sonnet 4.6 model page, the public model list and the price catalog. Date: 2026-09-24.

If you want to set up Claude Code, see the Claude CLI tutorial. For other providers' Taiwan payment options, compare OpenAI API procurement, Gemini API procurement and the cross-model price comparison. The original company billing and invoice sections are kept below. Actual vouchers always depend on the documents provided by the purchasing channel.

Claude's company name and Tax/VAT ID can be updated in billing settings, but "entering a tax ID" and "getting a Taiwan electronic unified invoice" are not the same thing. Before buying, first distinguish between website subscriptions, App store subscriptions, the Claude API, and API services bought from a Taiwan provider, then check the transaction documents for each.

This article reviewed Anthropic's official documentation on 2026-09-17. If your company needs a Taiwan three-part voucher, check the actual account and the documents provided by the purchasing channel before ordering. The official Tax ID field description is not a guarantee of an eGUI for every transaction.

Claude Pro/Max: where to enter the company title and tax ID

According to the official guide to Tax/VAT IDs for paid Claude accounts, related fields may appear during sign-up depending on your address and tax eligibility. For accounts that are already subscribed, update the payment method and Tax ID under Settings → Billing.

To show the company name on invoices, tick Use a different name on invoices when adding or updating a payment method, then fill in the company name and billing address. If the account does not show the expected fields, first check the region, payment channel and account, and then contact official support.

Changes only affect documents issued afterwards. Invoices already issued cannot be backfilled by changing settings, so for company purchases it is best to confirm the title, tax ID and payer name before paying.

Where to find subscription receipts

Pro/Max purchased on the website can be opened from the Invoices section under Settings → Billing, and you should check your billing email. Purchases through Apple or Google Play are handled by the store, and receipts are found in the corresponding store account. Do not look for store transactions via the website path. This distinction, along with the company name and old-document limitations, is explained in the official Pro/Max invoice guide.

After receiving an invoice or receipt, check the actual seller, buyer, tax amount and document type. An English title is not the basis for judgment, and a general invoice PDF cannot be treated as a Taiwan unified invoice just because of its name.

Claude API: the Console tax ID and vouchers are a separate system

Claude subscription credits are not the same as API prepaid credits, and an API organization's billing is not the individual Claude Billing page.

For the steps and document types, see the Console Tax/VAT ID guide and the Claude API invoice guide. Do not mix prepaid credit receipts, monthly usage invoices and individual subscription bills into one monthly report. The organization's company details also need to be set up before invoices are issued.

Can a Taiwan company expense it? Separate the two questions

Whether an expense can be deducted and whether business tax input can be credited are separate judgments. The absence of a Taiwan unified invoice does not by itself mean the expense cannot be recognized. Conversely, an English invoice with a title and tax ID does not mean the Taiwan input tax can be credited.

The Ministry of Finance's overseas electronic services guidance distinguishes between domestic businesses, government agencies and organizations, and natural persons. When the corporate buyer falls under Article 36 of the Business Tax Act and its purpose conditions, do not apply the arrangements an overseas vendor uses for individual consumers, and not every transaction is subject to another 5% tax. The original text of Article 36 is available for accounting to check.

If your company requires a three-part voucher, first have accounting confirm what documents this account and this purchase channel can provide, then decide on the purchase. Keep the bill, payment, purpose and purchase approval. Individual advance payments are not always illegal, but they must correspond to a real transaction and to the company's reimbursement process. For the full list of documents, see the AI API expense process.

When you need a Taiwan unified invoice, match the option to the product you buy

Claude Code's official enterprise deployment guide lists the different platforms and authentication paths. You cannot say across the board that switching cloud platforms requires rewriting all code, nor can you guarantee that every model, region and feature is identical just because a platform offers Claude. When continuing with an existing cloud contract, the invoice still depends on the actual contracting seller, not just the platform name.

When buying through other channels, first confirm the actual contract, license and seller. The invoice should correspond to that provider's real transaction. An unrelated official subscription cannot be used to issue a substitute invoice.

What Taiwan procurement documents BazaarLink can provide

BazaarLink's API service is provided by Jilian Technology Co., Ltd. (Tax ID 62232477), which can issue two- or three-part electronic unified invoices to buyers who meet the Taiwan transaction conditions. Before paying, companies should confirm the title, tax ID, channel and invoicing details. Monthly billing and enterprise purchase terms can be negotiated in advance, but they do not automatically apply to every account. The company and enterprise cooperation page lists contact details.

Current Claude models and customer prices can be viewed in the model catalog. Model usage fees, top-up and payment fees, and TWD conversion are checked separately. The unit prices in this article are not used in place of the current quote.

This invoice corresponds to the API service purchased from Jilian, and is not issued in place of an official Pro/Max or Claude Code subscription. If you need official product login, the chat interface or specific cloud workloads, look at the official plans first. Whether an API can connect to a given tool should be verified against the API docs and that tool's documentation. For sustained high usage, compare your subscription allowance with total API cost based on your own workload, not just model unit prices.

If you have a budget deadline, first confirm which dates the payment and delivery fall on

Research projects or public-sector procurement should first confirm the expense-claim deadline, acceptable vouchers, whether the prepaid credits fit the project, the service usage period, and whether subscription renewal needs separate approval. A subscription is not always unworkable, and a one-time top-up is not necessarily recognized in full once paid. Procurement, accounting and the user team need to align first.

For cancellation of renewal or refund requests, see ChatGPT and Claude cancellation and refunds. For official tool fees, see Claude Code fees.

TWD billing · Taiwan invoices · leading AI models · OpenAI-compatible API