Avoid ampersands in formal text as they can suggest carelessness or laziness. But use them if they are part of an official name or title, particularly for an organisation.

The ampersand is a character that can take the place of the word ‘and’.
Its shape comes from joining the letters ‘e’ and ‘t’. The word ‘et’ means ‘and’ in Latin. Its name is a corruption or contraction of the phrase ‘and per se and’ (& by itself equals and).
Avoid ampersands in formal text as they can suggest carelessness or laziness. But use them if they are part of an official name or title, particularly for an organisation.
Consider ‘&’ when citing sources with multiple authors
In formal writing, ampersands are more commonly used in reference lists to help abbreviate long titles, particularly where there are multiple authors.
The ampersand can also be useful in a document where space is tight, such as in tables or the captions and labels for graphs.