The five year number
Five years of A custom Excel spreadsheet comes to £424.95 on Microsoft 365 Personal paid annually. Software figures use Microsoft's published UK consumer prices on the annual Personal plan. Excel is not sold standalone: it comes through a Microsoft 365 plan or the free web version. Verified 21 July 2026.
Year by year
| Time held | A custom Excel spreadsheet | Delphina |
|---|---|---|
| After 1 year | A custom Excel spreadsheet£0 using Excel for the web, or £84.99 on Microsoft 365 Personal paid annually | Delphina£119.88 |
| After 3 years | A custom Excel spreadsheet£254.97 on Microsoft 365 Personal paid annually | Delphina£359.64 |
| After 5 years | A custom Excel spreadsheet£424.95 on Microsoft 365 Personal paid annually | Delphina£599.40 |
Delphina Wealth Builder at £9.99 a month, held flat.
Software figures use Microsoft's published UK consumer prices on the annual Personal plan. Excel is not sold standalone: it comes through a Microsoft 365 plan or the free web version.
Costs that are not on the price list
These do not show up when you sign up, but they show up on your statement.
- Hidden cost: Your time, which is the real price: building a usable retirement model is many evenings, and maintaining it never stops
- Hidden cost: Rebuilding the tax logic every time an allowance, band or threshold changes
- Hidden cost: The risk of a silent formula error producing a confident wrong answer for years
- Hidden cost: Manual data entry for every account, every month, because there is no Open Banking feed
- Hidden cost: Backing up and version-controlling the file yourself
Figures based on A custom Excel spreadsheet’s published prices(opens in a new tab), checked 21 July 2026.
What you are paying for
For people who want total control over every assumption and genuinely enjoy building the model, that is a fair price. Complete flexibility: if you can define the rule, you can model it, with no vendor deciding what is supported. No subscription lock-in to a planning vendor, and your file keeps working whatever happens to any company.
A five year total always looks large written down. Judge it against what the tool actually changes, not against the headline on its own.
Plans and tiers
This page is about the running total. For the tier structure and what each plan includes, see A custom Excel spreadsheet pricing.
The same five years on Delphina
Delphina's Free plan is £0 for as long as you want it, no card. Wealth Builder is £9.99 a month, so five years is £599.40 if you stay on it the whole time, billed in pounds with no FX fee.
A well-built spreadsheet is a legitimately excellent financial plan, and people who enjoy building one should build one. What it costs is your evenings, forever, and it will not tell you when you get an ISA rule wrong. Delphina is the same idea with the UK rules, the Open Banking feed and the maintenance already handled, from Free through £9.99 a month to £19.99 a month.
More on A custom Excel spreadsheet
A custom Excel spreadsheet: common questions
It is worth it for people who want total control over every assumption and genuinely enjoy building the model. It is a poor buy for anyone who needs every balance is entered by hand, so the model is out of date the moment you stop maintaining it, because that is not what it is built to do.
5 things are not on the pricing page: your time, which is the real price: building a usable retirement model is many evenings, and maintaining it never stops; rebuilding the tax logic every time an allowance, band or threshold changes; the risk of a silent formula error producing a confident wrong answer for years; manual data entry for every account, every month, because there is no open banking feed; backing up and version-controlling the file yourself.
Free tools in this category generally give up either the depth or the account connections. Delphina's free tier gives up the deeper scenario modelling that the paid plans carry, but costs £0 with no card and no expiry.