For an Umbraco 13 site moving to Umbraco 17, around 21 days end to end. That is the full journey: preparation, the upgrade itself, testing against your real content and integrations, and a cutover with no downtime. It is not 21 days of your team's time; your involvement is mostly at the start, telling us how the site is used, and at the end, checking the result. Sites on older versions, or with heavy customisation, need individual scoping because the effort depends on how much has to be rebuilt between versions. What keeps our timeline reliable is that we have upgraded Umbraco sites through every version since v4, so the surprises that derail first-timers are things we already plan for.
The honest answer has two parts: the elapsed time, which is around 21 days for a 13 to 17 upgrade, and the shape of that time, which matters more than the number.
The version bump itself is the quick part. Most of the time goes on the work around it: auditing the site and its packages before we start, rebuilding anything that changed between major versions, testing against your actual content rather than a demo, and rehearsing the cutover so the real one is uneventful. The cutover happens with no downtime, and the project includes 30 days of cover afterwards so anything that only shows up in live use is fixed as part of the job.
Three things, and we identify all of them before quoting: custom code that relies on APIs which changed between versions, third-party packages that have no modern equivalent and need replacing, and integrations that only exist on the live site with no documentation. This is why we scope first. When a site is several versions behind, or carries years of undocumented customisation, the honest timeline is longer, and we will tell you that up front rather than discover it on your invoice.
Umbraco 13 security support ends on 14 December 2026. A 21 day project sounds like something you can leave until November. In practice, everyone else has the same deadline, agency capacity will tighten through 2026, and sites that need remediation work first will want slack in the calendar. Booking earlier costs nothing extra and removes the risk entirely.
The full detail, including the £8,999 plus VAT fixed price and the 50/50 payment structure, is on our migrations and upgrades page. If your site is on an older version, tell us what you are running and we will give you a realistic timeline for it.
Tell us what you're working on and we'll come back within one working day.
An Umbraco Silver Partner agency in Llandudno, North Wales and the Isle of Man, building and looking after Umbraco and .NET websites for businesses and agencies across the UK and beyond. Simon Antony is a brand of Simplepage Ltd.
Maesgwyn, 3 Claremont rd,
Llandudno, North Wales, LL30 2UF