I don't currently have mains gas supply. How does this impact my quote/install?

You can still get a heat pump – they run on electricity, so mains gas isn't needed.

If you're currently heating your home with oil or LPG, you'll get the higher Boiler Upgrade Scheme grant of £9,000 (from July 2026 until the end of March 2027), rather than £7,500. Your estimate and proposal will reflect this.