Here are Mumbai hotels (and small groups) that publicly advertise “early bird” / advance-purchase rates — with the main booking condition and the source so you can check current availability and exact terms. Note: offers change often; the statements below are what I found on the hotels’ official offer pages (checked on Sep 14, 2025).

• The Oberoi, Mumbai — “Early Advantage Rate” (special savings for firm plans; applies when booked in advance; non‑cancellable once confirmed). Check the Oberoi Mumbai offers page for the exact advance window and cancellation rules. (oberoihotels.com)

• Taj Hotels (select Taj properties in India) — “Early Bird / Family Getaways / Royal Experiences” early‑bird packages (examples: up to ~25% savings on Taj Holidays packages when booked in the promo window; these offers include stay-date windows and blackout dates — validity periods are published on the Taj site). Confirm which Taj Mumbai properties participate and current validity before booking. (tajhotels.com)

• Four Seasons Hotel Mumbai — “Advance Purchase” (advertises up to ~20% off when you book a set number of days in advance; typically requires full prepayment and is non‑refundable). See the Four Seasons advance‑purchase terms for exact lead time and refund rules. (fourseasons.com)

• Dragonfly Hotel (Andheri) / Dragonfly Service Apartments — explicit “Early Bird” discounts (examples shown: 20% off when booking 7+ days ahead; other variants show 10% if booked 15 days ahead). Local property pages list the required advance window. (dragonflyhotel.in)

• The SunCity Hotels (Mumbai group) — advertises an “Early Bird” rate (e.g., book 7+ days ahead for up to ~15% off). Check the group’s offers page for participating properties and current terms. (thesuncityhotels.com)

• Theory9 / Theory9 Serviced Apartments (Bandra) — “Early Bird” promotion (example: book 7+ days in advance and get a discount, example shown 25% in the promotion). Confirm availability & exact lead time on the property page. (theory9.in)

Practical booking tips (important):

• “Early bird” / “advance purchase” rates frequently require a minimum lead time (commonly 7–30 days), are often prepaid and non‑refundable, and may have blackout dates — always read the offer’s T&C before paying. (See examples: Oberoi and Four Seasons terms.) (oberoihotels.com)
• Chain loyalty/member rates and promos sometimes stack differently (member‑exclusive deals can beat public advance rates) — check membership pages or sign in before booking. (marriott.com)
• Compare the hotel’s direct offer with OTA advance‑purchase deals (sometimes OTAs show similar advance discounts, but the hotel site may have membership perks or different cancellation rules).

If you’d like, I can look up current early‑bird availability and exact prices for specific Mumbai neighborhoods or travel dates (I’ll check the hotels’ offer pages and live rates).