Should I Use Primary Domains For Multiple Target Countries (Using Same Language)?

Topic summary

A Shopify store owner primarily targeting the UK wants to expand into other English-speaking markets (US, Canada, Australia) and is seeking guidance on the optimal domain structure.

Two options under consideration:

  1. Single primary domain - Use one domain for all English-language countries, potentially using payment solutions to handle currency differences

  2. Subfolder structure - Implement country-specific subfolders (e.g., xxxx.com/us, xxxx.com/ca) even though all markets use the same language

The question focuses on which approach provides better SEO performance and user experience for multi-country expansion within the same language market. The discussion remains open with no responses yet addressing the trade-offs between these domain strategies.

Summarized with AI on November 20. AI used: claude-sonnet-4-5-20250929.

Background:

My primary market is UK, I also want to expand to US / Canada / Australia (English-Language countries)
Question:

In such case, whats the best domains solution for SEO & User experience? ( I use shopify payments to solve currency issue)

1, I use only Primary domain, for all the English-Language countries.

2, I use subfolders , like XXXX, XXXX for different countries, even they use same launguage.

Thanks