Days 1 to 5: decide what you are launching
Write one sentence describing the service, not the software. For example: “Bookkeeping, VAT and a management pack, closed by the 12th of each month, on our own platform.” Every later decision should serve that sentence.
Collect brand assets now, because they are the slowest thing to chase internally: logo files in light and dark versions, brand colours as hex codes, the firm’s legal name and TRN for document footers, and a short product name. Many firms use the firm name plus “Books” or “Portal”.