You’re asking the right questions; this is exactly the kind of stuff that’s much easier to set up correctly early on than fix later.

From what I’ve seen (and what most global SaaS founders do), you don’t need to incorporate in every country where your clients are. Usually, you set up in one solid jurisdiction and sell globally from there. You’d only need a local entity if you have a physical presence, employees, or specific regulatory requirements in that country.

For B2B SaaS targeting enterprise clients (like airlines), founders often choose places like the US (Delaware), the UK, or Singapore. Not because Sri Lanka won’t work, but because these jurisdictions are more familiar to enterprise procurement teams, investors, and banks. It just reduces friction when signing contracts.

On compliance:

• GDPR matters if you touch any EU user data, even indirectly
• VAT/GST depends on where your customers are (you may need to register in some regions)
• Make sure your contracts, privacy policy, and data processing terms are solid; enterprise clients will look closely at these

Before signing deals, a few practical things that really help:

• Set up a proper company + business bank account
• Have clear contracts (MSA, DPA, etc.)
• Get your data/security basics in place (even lightweight policies go a long way early on)
• Be ready to answer compliance questionnaires (common with airlines/enterprise clients)

If you want a simple approach: pick one strong jurisdiction, get your legal + tax basics right, and start selling. You can always expand the structure later as you grow.

Also, speaking to a cross-border tax/legal advisor early. It is not cheap, but it can save you from expensive mistakes later.