User guide

A short guide to using Billero.

Quick start

• Fill in My details (IBAN, address, tax number …).
• Add clients (companies or individuals).
• Create a new invoice (simple or multi-item).
• You can share or save the PDF. Editing an invoice regenerates the PDF.

Multi-item invoice

• Each item has a description, quantity, unit, price and VAT rate.
• On smaller screens, fields automatically wrap into two rows for readability.

Sending invoices to a client

From a client's detail card you can quickly select and send multiple invoices at once.

• Open the Clients tab and tap a client.
• Long press an invoice → enters selection mode.
• Tap additional invoices to select or deselect them.
• In the title bar tap ↗ to share the selected PDFs.
• To exit selection mode tap ✕ in the title bar.

Works the same for companies and individuals (including the Unknown client).

Received invoices with AI OCR

Billero can automatically read the supplier, number, date and amount from a PDF invoice using AI (Anthropic Claude). The feature is optional and requires your own API key.

Getting an API key

1. Go to console.anthropic.com and create a free account.
2. In the menu select API Keys → Create Key.
3. Name the key (e.g. Billero) and copy it. The key starts with sk-ant-.
4. You need to add a payment method in the Anthropic console. Reading one invoice costs less than €0.001 (Claude Haiku model).

Setup in the app

1. Open My details (⚙ tab) → section Anthropic API key (OCR).
2. Paste the key into the field and tap Save.
3. The key is stored in the secure area of your device (Android Keystore) — it is never written to app files.

Usage

1. In the Invoices tab tap the ↑ icon (import PDF) and select the PDF of a received invoice.
2. A form opens. Tap the ✨ Analyse with AI button.
3. Wait a moment — the supplier, number, date and amount fields are filled in automatically.
4. Review and correct if needed, then tap Save.

Without an API key the form works as before — fill in all fields manually. The AI button will not appear.

Backup & restore

All your data (invoices, clients, settings and PDFs) can be exported and restored from the My details tab → Backup section.

Export

• Tap Export backup.
• The app creates a ZIP file (billero_backup_YYYY-MM-DD.zip) and opens the Share sheet.
• Save the file to iCloud, Google Drive, email, or anywhere you prefer.

Restore (e.g. after switching phones)

• Install Billero on the new phone.
• Open My details → Restore from backup.
• Confirm the warning (existing data will be replaced).
• Select the ZIP file from your storage location.
• All invoices, clients, settings, PDFs, logo and digital signature are restored.

Warning: restoring replaces all existing data. We recommend exporting a backup of your current data before restoring.

Recurring invoices

Billero automatically generates regular invoices (weekly, monthly or quarterly) each time the app launches.

1. In the Invoices tab tap the ↻ icon (top right) → Recurring invoices.
2. Tap + and fill in: template name, client, service description, amount (excl. VAT), VAT rate.
3. Choose frequency: weekly, monthly or quarterly.
4. For monthly/quarterly choose the day of the month (1–28).
5. On the next app launch on or after the scheduled date the invoice is automatically created with its PDF.

Templates can be disabled with the toggle or edited at any time. Generated invoices appear in the main invoice list.

Crypto payments

Billero supports two types of crypto payments: static QR codes on the PDF invoice and a Coingate payment link for accepting 70+ cryptocurrencies.

QR codes on PDF invoice — supported cryptocurrencies

Set your wallet address(es) in My details → Crypto payment. The QR code is automatically added to page 2 of every PDF invoice.

• EURC — Circle Euro stablecoin on Ethereum, Base or Solana. Rate: 1 EURC = 1 EUR.
• USDC — Circle USD stablecoin on Ethereum, Base, Polygon or Solana. Rate: fetched from ECB via Frankfurter API at PDF generation time.
• BTC — Bitcoin, BIP-21 QR format. Rate: fetched from CoinGecko at PDF generation time.
• ETH — Ethereum (native), EIP-681 QR format. Rate: CoinGecko.
• SOL — Solana (native), Solana Pay format. Rate: CoinGecko.
• Custom token — enter the token name and wallet address; the QR encodes the address (amount by agreement).

The rate and fetch timestamp are printed below each QR code. Without an internet connection the QR code is not shown (the rate must be fresh).

In My details → Display on invoice you can independently toggle the UPN QR and the crypto QR. UPN stays on page 1, crypto QR is on page 2.

Coingate payment link (BTC, ETH, SOL and 70+ coins)

1. Create an account at coingate.com and obtain an API key.
2. In My details → Coingate, enter your API key. Enable Sandbox mode for testing.
3. In the Invoices tab, tap the ₿ icon next to the invoice.
4. The app creates a payment link — a QR code and an Open in browser button appear.
5. Share the link with your customer. They pay with any cryptocurrency they choose.
6. You receive EUR to your bank account via SEPA (Coingate handles the conversion).
7. Check payment status with the Check status button in the app.

Coingate is EU-regulated (EMI licence, Lithuania) and supports SEPA payouts.

Thailand — bilingual PDF (Thai + English)

When your profile is set to Thailand (TH), Billero automatically generates a bilingual PDF invoice: every label is printed in Thai script (above) and English (below) side by side on the same page.

• Thai font (Noto Sans Thai) is bundled with the app — no installation needed.
• Works for local Thai clients and for international clients who do not read Thai.
• VAT rate: 7% (Revenue Code, Section 77). Registration threshold: THB 1,800,000/year.

Singapore — GST invoice

When your profile is set to Singapore (SG), Billero automatically applies GST rules:

• GST rate: 9% (GST Act, Chapter 117A).
• Registration threshold: SGD 1,000,000/year — below the threshold a disclaimer is printed.
• Currency: SGD ($). Payment terms: 30 days.