The customer name on my invoices is very small how can I increase the font size
Are you saying it is smaller than, for example, the billing address or your company’s address? In the default theme, all text is the same size except the form title and the summary level description.
Or are you just saying you want to make the customer’s name larger? If so, you need a custom theme. If you don’t have the programming skills, hire a local programmer to write one for you. See https://www.manager.io/guides/10368.
The customer’s name is small in the invoice
It would be clearer what you mean by small if you posted a screen image of the invoice and details of any custom themes used?
Also what version are you using and on what machine?