Vaccination and health: not required.

No visa is required if staying for only thirty (30) days.

Documents to present:

1. Valid passport with six months.
2. Round trip tickets to and from another country.
3. Economic solvency during the days of your stay.

If you are going to stay more than 30 days in Belize, you must go to an Immigration Office to extend your stay in Belize. The permit required to extend your stay in Belize beyond 30 days is the "Belize Visitor's Permit Extension".

The extension of the visitor's permit allows the visitor to remain in the country provided that the holder does not engage in any paid or unpaid activity, does not engage in any commercial or professional activity without the consent of the Director of Immigration and does not remain in Belize beyond the expiration date of the permit.

• The Visitor's Permit Extension allows you to remain in Belize for an additional 30 days.
• All fees are in Belize dollars.
• The Visitor Permit Extension fee is BZ$200.00 for all nationals.

Who qualifies

• Persons wishing to extend their vacation in Belize or persons investigating settlement possibilities.
• Persons requiring a visa (see Visas section) after a predefined number of extended days in Belize must acquire such a visa before being issued an extension of the visitor's permit.
• Belize visa holders are eligible for a visitor's permit extension.

More details  here.

More information here.