Cross-Border Payments & Compliance for Solo Developers

You shipped a product. A customer in Germany wants to pay you, and you live in Brazil. Suddenly you're not just a developer — you're running a small financial operation with tax and regulatory exposure in multiple jurisdictions. This guide covers the practical setup that works for one-person companies, not the enterprise playbook.

Pick Your Payment Rails Before You Pick a Bank

Most solo developers overthink the banking side and underthink the payment side. Start with how money will actually arrive.

Card payments (Stripe, Paddle, Lemon Squeezy): The easiest path. Stripe works in ~45 countries; Paddle and Lemon Squeezy act as Merchant of Record (MoR), meaning they handle sales tax/VAT and you receive a single payout. The MoR model is the single biggest compliance shortcut available to solo devs — you trade ~5% fees for not registering for VAT in 30 countries.

Bank transfers (Wise, Payoneer): Cheap for B2B invoices but you own the invoicing and tax collection. Wise Business gives you local account details (IBAN, US routing number) in multiple currencies, so customers pay domestically.

Crypto (USDC, BTC): Only if your customers demand it. Accounting is painful and some jurisdictions treat it as a taxable disposal on every transaction.

My recommendation for most solo devs: use an MoR for consumer/SMB sales, and Wise for direct B2B contracts. You get compliance coverage plus low-cost international transfers.

Understand Where You Actually Owe Tax

The two taxes that bite solo developers are VAT/GST (consumption tax) and income tax.

For digital services sold to consumers (B2C), the destination country typically claims VAT. The EU's OSS scheme, UK VAT registration (£90k threshold for non-established sellers is effectively zero), and Australia's GST on digital goods all apply. This is why the MoR route matters — the platform is the seller of record.

For B2B sales, the reverse-charge mechanism usually applies: the buyer self-assesses VAT, and you invoice with a note like "VAT reverse charged — Article 196, Directive 2006/112/EC." No registration needed in most cases, but you must collect and store the customer's VAT number and validate it via VIES.

Income tax is simpler conceptually: you pay where you're tax-resident. But watch for permanent establishment rules — if you work from a country for months, you may create a taxable presence there. Keep trips short and document your tax residency.

Invoicing and Record-Keeping That Survives an Audit

Every cross-border invoice needs: your legal name and address, the customer's name and address, a sequential invoice number, date of supply, description, unit price, VAT rate and amount (or reverse-charge note), and your tax ID. Missing any of these can invalidate the customer's VAT deduction and get the invoice rejected.

Automate this. A small script or a tool like Invoice Ninja can generate compliant PDFs from your database. Store invoices for the legally required period — typically 7–10 years in the EU, 7 in the UK, 5 in many other places. Keep them in a cloud bucket with versioning, not a local folder.

For currency conversion, record the exchange rate on the invoice date. Use a published rate (ECB, your bank's) and be consistent.

Banking, FX, and the Hidden Costs

A common mistake: receiving USD into a local account and letting the bank convert at 3–4% spread. Instead:

• Open a Wise Business or Payoneer account for multi-currency holding.
• Invoice in your customer's currency (USD, EUR) to avoid surprising them.
• Convert to your home currency in batches when rates are favorable, or on a fixed schedule to avoid FX speculation.

Keep business and personal money strictly separate. Even as a sole proprietor, a dedicated business account simplifies bookkeeping and looks professional on invoices. If you incorporate (LLC, Ltd, GmbH), you'll need it anyway.

A Minimal Compliance Stack

Here's a lean setup that covers most solo developers:

1. MoR platform (Paddle/Lemon Squeezy) for consumer SaaS and digital products.
2. Stripe for B2B card payments where you control invoicing.
3. Wise Business for receiving bank transfers and holding currencies.
4. Accounting tool (Wave for free, Xero/QuickBooks if you need VAT filing) connected to your bank feeds.
5. A folder structure — /invoices/2025/, /receipts/2025/, /contracts/ — synced to cloud storage with versioning.
6. A calendar reminder for quarterly VAT/estimated tax filings in your jurisdiction.

Budget two to three hours per month for reconciliation. It's boring but it prevents the panic of a tax authority letter you can't answer.

Next Steps

1. Audit your current sales flow. List every country your customers come from and how they pay. Identify any B2C digital sales where you might owe VAT/GST.
2. Decide on MoR vs. direct. If you sell B2C globally, move to an MoR platform. If you sell B2B, set up Stripe + Wise and validate VAT numbers.
3. Open a multi-currency business account this week. Wise Business takes about 20 minutes.
4. Build an invoice template with all required fields, including reverse-charge notes.
5. Talk to a local accountant once. A one-hour consultation about your specific cross-border situation costs less than a single misfiled VAT return. Ask specifically about permanent establishment risk and digital services VAT.
6. Set up automated backups of invoices and receipts to cloud storage with versioning enabled.

The goal isn't to become a tax expert — it's to build a system where compliance happens by default, so you can get back to shipping code.