Biweekly, without the hyphen or space, is the standard and correct spelling. However, ‘bi-weekly,’ with a hyphen, is also considered correct and used by some people, though it is not as common. In terms of meaning, ‘biweekly’ can indicate either occurring once a week or occurring every two weeks, but the latter  is more common.

Lets see the differences between biweekly, bi-weekly and bi weekly below

Biweekly 

The term Biweekly is the standard spelling and it is formed by combining the prefix bi and the root word weekly.  Furthermore biweekly is most commonly used in American English to mean one every two weeks. 

In British English, fortnight is more commonly used to mean ‘once in every two weeks.However, In American English you would say  “biweekly” to mean  once every two weeks but you would say  “semi-weekly” to mean twice a week. 

However, In  British English Biweekly means twice a week and hence fortnight is a common word to mean once in two weeks. 

Because biweekly has two meanings, just make sure to add some context when you are using it to make it clear about what you mean. 

Alternatively you can say twice a week or once in two weeks

• The tech company conducts bi-weekly training sessions to enhance skills.
• The magazine published biweekly articles on the latest trends in technology.

• Employees receive biweekly updates on company policies and announcements.
• The school organizes biweekly field trips to enhance students’ learning experiences.
• The company issues bi-weekly challenges to encourage employee creativity.
• The city’s transportation system introduces biweekly maintenance checks to improve 

Bi-Weekly

The term Bi-weekly may also mean  twice per week or once every two weeks. Bi-weekly with the hyphen between the prefix b and the root word weekly  was commonly used in the ealy1900s.

In modern English, this is not used often but some people do use it. Even though it is not endorsed by many guiding stylebooks,  it still remains  grammatically correct.

• We receive bi-weekly progress reports from the construction site.
• I attend bi-weekly yoga classes to stay flexible and relaxed.
• I visit the farmer’s market bi-weekly to stock up on fresh produce.

• Our support team sends out bi-weekly newsletters with helpful tips and updates.
• We schedule bi-weekly family game nights for quality bonding time.
• The software company releases bi-weekly updates to improve user experience.

So, while both biweekly and bi-weekly remain correct spelling, writing bi  weekly with a space between the prefix and the root word is incorrect and you should avoid it.

Bi weekly

The term bi weekly with the space in between is incorrect and you should avoid using it.

Let’s look at examples of sentences using “bi weekly” with a space:

Incorrect: I check my email inbox bi weekly for updates.

Correct: I check my email inbox bi-weekly for updates.

Incorrect: Our hiking group meets bi weekly for trails.

Correct: Our hiking group meets bi-weekly for trails.

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Incorrect: The podcast releases episodes bi weekly.

Correct: The podcast releases episodes bi-weekly.

Incorrect: Our study sessions are biweekly for exams.

Correct: Our study sessions are bi-weekly for exams.

Incorrect:I visit the art gallery biweekly for exhibits.

Correct: The support hotline is available biweekly.