Do I need GST registration for freelance design work billed only to US clients?

Exports count towards the ₹20 lakh threshold, so at ₹18 lakh you are close. Registration is optional today and becomes compulsory in the month you cross the limit; apply within 30 days of that date.

Your services are an export under section 2(6) of the IGST Act: the recipient is outside India, the place of supply is outside India, and payment is received in convertible foreign exchange (Wise and PayPal settlements into your Indian account qualify; keep the FIRC or payment advice for each receipt). Exports are zero-rated. File a Letter of Undertaking (Form RFD-11) on the portal and invoice without IGST, or pay IGST and claim it back. Almost everyone files the LUT; it is free and is renewed every April.

Many freelancers register voluntarily before the limit because registration lets you claim input tax credit on software subscriptions, laptops and co-working rent, and a GSTIN reassures larger clients. The cost is a monthly GSTR-1 and GSTR-3B (or quarterly under the QRMP scheme since your turnover is under ₹5 crore).