It's okay to use an ampersand (&) any time you don't feel like writing out the word "and."

The ampersand (&) is an often over-used abbreviation for the word and. Its use should be limited to a few situations.

We use an ampersand:

• in certain company names; e.g. Smith & Jones Consulting;
• if space is very limited; e.g. in a table with a lot of text;
• when artistic considerations dictate; e.g. a logo; and
• in some academic references; e.g. (Grant & Smith, 1998).

Do not use an ampersand in general writing simply to abbreviate the word and. For example, we write:

• We need to reorder toner cartridges and paper.

not:

• We need to reorder toner cartridges & paper.