OCR API Top-Up Guide: Official, Gateway, and Invoices (2026)

OCR is a pay-as-you-go service, and the account balance determines whether calls can continue. Teams in mainland China often get stuck on a few concrete questions: should they top up on the vendor's own platform or through a unified gateway; how do they pay a US-dollar bill; can they get an invoice; and who watches the balance as it runs low?

This article breaks the topic down by top-up path, currency, invoices, alerts, and procurement process. Prices, exchange rates, and invoicing rules are subject to the on-site model pricing page and platform terms.

Note: OpenAI, Google, Microsoft, Baidu AI Cloud, Alibaba Cloud, Tencent Cloud, and other names mentioned in this article are trademarks of their respective owners. This article uses common top-up models as of October 2026 as examples; payment methods, invoice rules, and service terms may change, so check the official pages before acting.

1. Distinguish the three top-up targets first

"Topping up OCR" can refer to three completely different kinds of account: a mainland cloud vendor, an international cloud vendor, and a unified AI gateway. Separate them first, then discuss which path fits you.

Path	Best for	Settlement	Invoice	Main constraints
Mainland cloud vendor platform	Teams with a cloud account, stable usage, and reliance on the cloud ecosystem	Corporate transfer, Alipay, WeChat Pay, and similar	Usually VAT invoices, subject to platform rules	Resource-pack specs and validity, endpoint binding
International vendor platform	Overseas entities with a foreign-currency card using a single vendor	Credit card or foreign-currency settlement	Most do not provide Chinese VAT invoices	Exchange rates, card-network fees, payment failures
AI gateway (ZSQH AI Gateway)	Teams calling multiple models, settling in RMB, and minimizing account maintenance	On-site top-up	Apply according to on-site rules	Available models and prices follow the pricing page

None of the three paths is universally better. If you already have a cloud account and use one vendor, direct top-up is simplest; if you use several models and need RMB billing and one key, a gateway saves management cost. Migration and reconciliation time are also costs, so do not move balances back and forth for a very small price difference.

2. Official top-up flow and common blockers

Topping up on a cloud vendor's own platform generally follows these steps:

Register an account and complete real-name or enterprise verification, and confirm that the verified entity matches the invoice title.
Activate the OCR service and confirm whether billing is postpaid, prepaid resource packs, or tiered usage.
Choose a top-up amount or resource-pack specification, and note the applicable endpoints, region, and validity period.
Create an Access Key or API Key, and set call quotas and alerts.
Validate recognition quality and billing behavior with a small set of real images, then scale up gradually.

Common blockers include:

Resource pack does not match the endpoint: a general recognition pack often cannot cover high-precision or document-parsing endpoints.
Free quota runs out: after a trial quota expires, billing may switch to postpaid automatically and the bill can jump.
Service suspension for arrears: service stops when the balance is insufficient, and restoration may be delayed.
Concurrency limits: QPS or concurrency quotas are unrelated to the top-up amount and must be requested separately.
Entity mismatch: enterprise verification, payer, and invoice title do not match, so reimbursement is easily rejected.

These rules differ by platform; confirm each item in the console or documentation before activation.

3. Gateway top-up flow

A gateway is positioned as a unified entry point: one account, one key, RMB settlement, and different models behind it. OCR is usually performed through vision-capable models; whether a given image type and layout is supported depends on on-site documentation and model pricing.

Create an account on the sign-up page and complete any required verification.
Open the wallet or top-up page, choose an amount and payment method, and confirm the crediting time.
Create API keys per project; do not let several people share one key.
Point base_url at the gateway address and call vision models in an OpenAI-compatible way.
Top up a small amount first and get a request working, then add funds based on real usage.

After topping up, verify authentication, model name, and quota with a minimal request:

export ZSQH_API_KEY="sk-your-key"

curl "https://ai.zhongshangqihang.com/v1/chat/completions" \
  -H "Authorization: Bearer $ZSQH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "a vision model name supported on-site",
    "messages": [{
      "role": "user",
      "content": [
        {"type": "text", "text": "Read the text in the image and output only the text."},
        {"type": "image_url", "image_url": {"url": "https://example.com/invoice.jpg"}}
      ]
    }]
  }'

Model names, image formats, and size limits follow on-site documentation. A successful top-up does not prove the endpoint works; verify authentication with a minimal request first so you do not misdiagnose a configuration problem as a balance problem.

4. Currency, exchange rates, and fees

Billing currency: mainland platforms mostly use RMB, international platforms mostly use USD. Confirm which currency the page shows when topping up.
Exchange rate: international platforms convert at the settlement rate, which changes daily; do not budget as if the rate were fixed.
Card-network fees: overseas payments may incur currency-conversion fees depending on the issuing bank.
Payment failure: risk controls, 3-D Secure verification, and billing-address mismatches can all cause failures, and repeated failures may temporarily restrict the card.
Refund exchange loss: after a foreign-currency top-up, converting a refund back to RMB may lose value because of the exchange rate.

When comparing cost, include exchange rates, fees, invoice deductibility, and manual operations together. Looking only at the list price easily leads to the wrong conclusion. The gateway displays prices in RMB; specific conversion and billing rules follow the model pricing page.

5. Invoices and enterprise procurement

Enterprise procurement usually passes four gates: contract, payment, invoice, and acceptance.

Contract and order: confirm the service scope, billing method, balance validity, refund terms, and data terms.
Paying entity: the payer on a corporate transfer should match the contract entity and invoice title.
Invoice type: confirm whether it is a regular or special VAT invoice and which category the invoice content falls under.
Invoicing timing: some platforms allow an invoice request after top-up, some invoice by actual consumption, and some require separate materials.
Overseas platforms: most do not provide Chinese VAT invoices and can provide only receipts or statements; confirm with finance before reimbursement.

If the team needs RMB payment, a contract, and invoices, a gateway is usually more compliant than paying with an individual credit card. Whether invoicing is available, the cycle, and required materials follow on-site instructions.

6. Balance alerts and quota management

Balance threshold alerts: set two levels, one to remind you to top up and one to notify the owner.
Auto top-up: enable it if available, but set per-transaction and monthly caps so anomalous calls cannot drain the balance.
Keys per project: create separate keys for testing, production, and different customers to simplify quotas and reconciliation.
Member permissions: separate permission to top up, request invoices, and create keys; do not let every member change payment settings.
Usage dashboard: review call volume, failure rate, and cost per page daily, and investigate retries and script loops first when usage rises abnormally.

Balance alerts only detect "the money is running out", not "the money is being spent wrongly". Reconcile usage logs with business volume once a week to find idle batch jobs or duplicate submissions.

7. Refunds, validity, and security

Whether unused balance is refundable, and how, differs by platform terms; confirm before topping up.
Promotional balance and coupons are usually non-refundable and may have usage-order restrictions.
Prepaid resource packs often have an expiry date and may become invalid if unused.
Consumed amounts generally cannot be refunded; in a dispute, the order and bill are the reference.
Do not use "low-cost top-up agents" or personal accounts, and never give anyone your account password or full key.
Confirm the payee name and domain, and keep order numbers, payment receipts, and invoices.

The key to top-up security is knowing who received the money and whom to contact if something goes wrong. For enterprise top-ups, use corporate processes where possible; for individual testing, start with a small amount.

FAQ

After topping up, why does OCR still say the balance is insufficient?

Common causes include delayed crediting, a quota cap on the key, calling an endpoint that has not been activated, or the balance being shared with other projects. Check the balance and key limits first, then the error code in the logs.

Is an official top-up or a gateway top-up more cost-effective?

Include exchange rates, fees, invoice deductibility, access stability, and operations time. Comparing unit prices alone ignores the last four, which are often the costs the team actually bears.

Can an overseas OCR platform issue a Chinese VAT invoice?

Most overseas platforms do not provide Chinese VAT invoices, usually only receipts or statements. Whether reimbursement is possible depends on finance policy; confirm before procurement.

Does the balance expire? Can unused funds be refunded?

It depends on platform terms. Prepaid resource packs often have an expiry date, promotional balance is usually non-refundable, and refund rules for cash top-ups vary. Read the terms before topping up and keep screenshots.

What materials are needed for enterprise procurement?

Usually a business license, contract or purchase order, corporate payment receipt, invoice information, and acceptance records. When ID documents and invoices contain sensitive data, also confirm data-storage region, retention period, and deletion method.

Next steps

Register and top up a small amount through ZSQH AI Gateway, get one OCR request working, then decide the top-up cadence based on real usage. Prices, billing methods, and invoicing rules are subject to model pricing and on-site instructions.