Extra Phone Number (Mobile)

Could do with the option for both and landline and mobile number for each company with both fields being available for including on invoices.

Are you referring to your client details? If this is the case you can already add two phone numbers to the contact details section:

I’m not sure why you would want to include your clients contact numbers on an invoice you’re issuing to them?

No. Company details not client. Only seems to be room for either a landline or a mobile but not both

Oh I see, I will recommend that this be considered in future updates. One thing you can do in the mean time is place some text directly below the sender details (i.e. you) on the invoice. Take a look in the invoice customisation area and click the sender address box: