An international tax lawyer is engaged in advising companies and individuals on tax issues related to international transactions. This includes:

- International tax planning: developing strategies to minimize or optimize taxes in international transactions and investments.

- Agreements between countries: Advising on tax treaties between countries and helping to resolve conflicts arising from different tax laws.

- Transfer pricing: advising on the pricing of internal transactions between different subsidiaries of a company in different countries.

- Compliance: advising on compliance with international tax laws and preparing returns for taxes such as income tax, VAT and customs duties.

- Mergers and acquisitions: advising on the tax implications of mergers and acquisitions between companies operating in different countries.

- Expatriate and Inpatriate Taxes: Advising companies and individuals on the tax implications of working abroad or hiring foreign workers.

- Tax Disputes: Helping to resolve disputes with tax authorities in various countries.

In short, an international tax lawyer advises on tax matters related to cross-border transactions, helping companies and individuals comply with the tax laws in the countries where they operate.