Xero handles your Derry firm's sterling books beautifully, then euro invoices and Irish VAT go in a spreadsheet on the side
Custom or extended accounting software for a Derry firm costs $35k to $95k over 3 to 6 months. You build beyond QuickBooks, Xero or FreshBooks when dual-currency books and two VAT regimes, UK and Irish, are forcing your finance team to keep the cross-border half of the accounts in a spreadsheet alongside the tool. This is the exact pain the profile names: tools that handle UK and Ireland invoicing and currency poorly.
Xero and QuickBooks are superb for a single-country business. The moment a Derry firm raises euro invoices to ROI customers, costs sit in sterling, and you owe VAT to both HMRC and Revenue, the tool starts leaking the cross-border work into spreadsheets. The euro invoices get hand-converted, the Irish VAT gets tracked separately, and reverse-charge on cross-border B2B becomes a manual judgement someone makes each time.
This is precisely the pain small software and medical-device firms in the North West describe: they win cross-border contracts, then wrestle with separate UK and Ireland invoicing and currency rules their accounting tools handle poorly. The books technically balance, but only because a person is quietly doing the cross-border accounting by hand, and that person is a single point of failure every reporting period.
Budgeting a accounting build in Derry
| Project scope | Typical cost | Timeline |
|---|---|---|
| Cross-border VAT + multi-currency extension over Xero/QuickBooks | $35k to $55k | 3 to 4 months |
| Custom dual-VAT, dual-currency accounting core | $65k to $95k | 5 to 6 months |
| Cross-border VAT and reconciliation module | $20k to $35k | 6 to 10 weeks |
The case for owning your accounting
Custom accounting software, or a serious extension of what you have, encodes both VAT regimes and holds both currencies honestly, so the cross-border work stops living in a spreadsheet. Euro invoices carry their real settlement rate, Irish VAT and reverse-charge are computed automatically, and both UK and Irish filings come out of one system. For a North West firm whose painful edge is exactly this dual-VAT, dual-currency invoicing, that turns a manual, single-point-of-failure process into something the books just do.
- Your finance team keeps the cross-border accounts in a spreadsheet beside Xero or QuickBooks
- You file VAT to both HMRC and Revenue and the single-country tool can't produce both cleanly
- Euro invoices are hand-converted and hidden FX losses are eroding margin
- Cross-border profitability is only visible after a manual period-end reconciliation
- You operate in one country and one currency and Xero or QuickBooks fits
- Your cross-border activity is rare enough to handle manually without strain
- You value the accountant ecosystem and familiarity of off-the-shelf accounting
- You lack capacity to own and maintain regulated accounting software
What your build should include
Derry accounting: the full scope
Digital Heroes builds the full accounting stack for Derry teams. Typical engagements cover expense management, custom accounting software, QuickBooks integration, Xero integration, invoicing software, bookkeeping software and financial reporting.
Delivery, week by week
Exactly what you get
You get accounting where the cross-border work lives in the books, not a spreadsheet. Euro invoices carry their real settlement rate, Irish VAT and reverse-charge are computed automatically, and both your HMRC and Revenue filings come out of one system. Cross-border profitability is visible directly, and the finance person who used to do this by hand stops being a single point of failure. It connects to your ERP, CRM and inventory management software so there's one financial truth.
How to choose a developer in Derry
This is the most regulated build on the list, so the bar is high. Ask the developer to explain reverse-charge on a cross-border B2B sale and how they'd produce both a UK and an Irish VAT filing from one ledger. If they can't, walk. Given how specific North West cross-border accounting is, favour a team that has built financial software before and will work alongside your accountant, not around them.
- Both VAT regimes encoded so HMRC and Revenue filings come out of one system, not a spreadsheet
- Euro invoices held with their real settlement rate, ending hand-conversion and hidden FX losses
- Reverse-charge on cross-border B2B computed automatically instead of judged by hand each time
- Cross-border profitability visible directly rather than after a period-end reconciliation
- Clean links to your ERP, CRM and inventory management software so the dual-currency truth is consistent
- You take on keeping UK and Irish VAT rules current as HMRC and Revenue change them
- Full accounting is heavily regulated; a complete custom ledger is a serious, costly undertaking
- You may lose the accountant-friendly familiarity and ecosystem of Xero or QuickBooks
- For a single-country business, Xero or QuickBooks is cheaper, compliant and entirely sufficient
- !They treat multi-currency as solved by a setting. Ask how the real settlement rate is captured per invoice
- !No grasp of reverse-charge. Ask them to explain VAT on a cross-border B2B sale to an ROI customer
- !They can't produce both filings. Ask how HMRC and Revenue VAT both come out of one system
- !They underestimate accounting regulation. Ask how they ensure the ledger stays compliant
- !No integration plan. Ask how the accounting truth stays consistent with the ERP and CRM
If accounting is on the roadmap, warehouse management, field service management, erp usually follow within the year. Budget them as one conversation.
Rohan advises mid-market and enterprise teams on ERP, CRM and custom software, and has led delivery on dozens of business-software builds.
Writes for Digital Heroes, shipping business software for 2,000+ brands across 55+ countries since 2017.
Frequently asked questions
Why can't Xero or QuickBooks handle our cross-border accounts?
They're built for one country and one VAT authority. A Derry firm raising euro invoices, costing in sterling and filing VAT to both HMRC and Revenue ends up keeping the cross-border half in a spreadsheet. This is the exact pain North West firms describe: tools that handle UK and Ireland invoicing and currency poorly.
How does custom accounting handle two VAT regimes?
It encodes both UK and Irish VAT rules, including reverse-charge on cross-border B2B, and produces filing-ready outputs for HMRC and Revenue from one set of books. The right treatment is applied per transaction automatically rather than judged by hand each time.
Do we need a full custom ledger or an extension?
Often an extension is enough: keep Xero or QuickBooks for the core ledger and statutory filing, and build the cross-border VAT and multi-currency logic around it for $35k to $55k. A full custom dual-VAT, dual-currency core is $65k to $95k and only worth it when the off-the-shelf core genuinely can't keep up.
How are euro invoices valued correctly?
The ledger captures the real settlement rate from the bank feed for each euro invoice rather than a daily average, so reported margins reflect what actually hit the account and hidden FX losses stop quietly eroding profit.