Cerillion PLC (AIM: CER) — Investment Research Note
Executive summary
Cerillion is a UK-listed vertical SaaS vendor selling a product-centric BSS/OSS suite (billing, charging, CRM) to ~70 telecom customers in ~45 countries, with c. 50% adjusted EBITDA margins and a 25-year track record. Across FY21-FY25 revenue compounded from £26.1m to £45.4m and adjusted PBT from £8.5m to £21.8m, with EBITDA margins expanding from 40% to 51%; H1 FY26 saw a deliberate licence-revenue phasing into H2 (revenue -14%, PBT -41%) while the £42.5m Omantel win in January 2026 took the back-order book to a record £82.1m. The single most important valuation point is whether the H2-weighted FY26 lands consensus and whether the Omantel contract de-risks FY27 — at £404.7m mcap the shares price in continued execution rather than the upside scenario.
Fair value estimate
- Methodology: Forward earnings multiple on FY27e adjusted EPS, cross-checked against EV/EBITDA.
- Key assumptions:
- FY25 adj EPS 56.5p; FY26 consensus implies broadly flat-to-modest growth (management: "well-positioned to deliver consensus market expectations") → ~58p 2026-06 H1 interim.
- FY27 benefits from Omantel licence recognition (c. 39% of £72.6m contracted-but-not-yet-recognised expected within 12 months from 31 March 2026) plus pipeline conversion → ~72-78p.
- Peer software multiples on vertical SaaS with 50% EBITDA margins, net cash, and a sticky telco customer base support 20-26x forward.
- Fair value range: 1,450p – 1,900p per share → mcap range £428m – £561m.
- Mid-point: ~1,675p, ~£495m mcap (≈ 23x FY27e adj EPS of ~73p, EV/FY27 EBITDA ~16x on £30m).
- Latest disclosed mcap £404.7m (~1,371p). Upside to mid: ~22%, downside to low ~+6%, upside to high ~+39%.
Sector context
- ICB Technology / Software — accurate.
- Quality (margin, balance sheet, recurring revenue ratio) is above typical AIM software peers; growth was very strong (FY22-FY23) and has decelerated as the base has grown.
- Listed peers: Amdocs (NASDAQ: DOX) and CSG Systems (NASDAQ: CSGS) at the large end; Comviva, Optiva (TSX: OPT) at the mid-end; Beeks Financial Cloud and Sopheon as UK micro-cap vertical-SaaS comparators in disclosure style.
Investment thesis
- Record back-order book and step-change in deal scale. The £42.5m, 5-year Omantel contract signed January 2026 is c. 70% bigger than the previous record (£25.3m European deal). Back-order book up 64% YoY to £82.1m, pipeline up 4% to a fresh high of £271m after closing Omantel — multi-year revenue visibility is the best in the company's history 2026-06 H1 interim.
- High operating leverage at scale. FY25 gross margin 81.5% and adjusted EBITDA margin 50.9% (up from 47.4% FY24, 46.2% FY23, 42.0% FY22) demonstrate the fixed-cost dynamics: incremental software-licence revenue drops to PBT at near-90% incremental margin. The H1 FY26 mechanics make the leverage explicit — a £2.9m revenue drop produced a £3.8m PBT drop 2025-11 FY25 results; 2026-06 H1 interim.
- Fortress balance sheet plus growing recurring base. £32.5m net cash, no meaningful debt, £19.1m ARR (+5% YoY), and dividend cover supported by ~50% of FCF — provides downside protection while the management team executes on long-cycle wins. CEO Louis Hall has run the business since the 1999 MBO from Logica 2026-06 H1 interim.
Key risks
- Customer concentration. FY25 saw single customer No. 1 contribute £13.1m (29% of revenue, up from £9.3m FY24); FY23 had three >10% customers. Loss of a single anchor customer would materially affect margins given the high incremental-margin model 2025-11 FY25 results.
- Licence-revenue lumpiness creates forecast risk. H1 FY26 revenue -14%, PBT -41%, with "vast majority of FY26 software licence revenue" pushed to H2. Full-year delivery is therefore concentrated into roughly four months — any slippage in Omantel or term renewals will miss consensus 2026-06 H1 interim.
- AI substitution debate. Management explicitly addresses the risk that telcos "in-source" BSS/OSS via AI, arguing deterministic billing is unsuited to probabilistic AI generation. This is a defensible view but not a settled question — the multiple compresses if the market reframes vertical SaaS as exposed to AI displacement 2026-06 H1 interim.
Operating leverage
Cerillion is a high-fixed-cost software business with c. 76-82% gross margins and operating expenses of £16.7m in FY25 against £45.4m revenue. Personnel costs (£10.2m) and capitalised R&D (£1.8m additions) are the dominant fixed components, with delivery teams concentrated in lower-cost India and Bulgaria. The natural test of leverage is the H1 FY26 print: revenue down £2.9m, gross margin down 480bp (from less licence mix), but operating expenses up £0.7m (continued investment in headcount) — net effect was a £3.8m PBT decline on a £2.9m revenue decline, implying incremental-revenue drop-through above 100% in the reverse direction. Symmetrically, on an upside revenue surprise of 15-20% above plan (say +£8m), with the cost base broadly fixed and licence-heavy mix, operating profit could plausibly grow 50-70% versus base case. The 350bp annual margin expansion through FY23-FY25 demonstrates this in practice. Note the back-order book of £82.1m versus £45.4m FY25 revenue is unusually large relative to cost base, so the FY27 Omantel licence recognition is the closest thing to an observable inflection.
Value-trap signals
None identified. Net cash rising, no dividend cuts (up 17% to 15.4p FY25), unqualified audits, no related-party flags, end-market spending broadly supportive. The H1 FY26 weakness is timing not structural.
Earnings vs. expectations
The Oct 2024 trading update flagged FY24 PBT "comfortably ahead" of the £17.9m consensus (delivered £19.8m, +11% beat). Oct 2025 update flagged FY25 PBT "slightly ahead" of £20.5m consensus (delivered £21.8m, +6% beat). Oct 2023 update flagged FY23 PBT "meaningfully ahead" of £14.3m consensus (delivered £16.8m, +17% beat). The Apr 2024, Apr 2025 and Apr 2026 H1 trading updates each matched the H1 print within the published ranges. Pattern: consistent material beats vs. management-set consensus, no missed years across the period covered.
Conviction
Conviction: 4 (high). Anchors: (a) 5-year track record of clean, consistent disclosure with consensus beats; (b) the £82.1m back-order book and signed Omantel contract make the FY26/FY27 fair-value bridge concrete rather than speculative; (c) the business model (subscription/licence vertical SaaS, fortress balance sheet, founder-CEO) is unambiguous and easy to model. Limits: (a) FY26 outcome depends on H2 licence-revenue timing, which has slipped historically; (b) AI displacement risk is real even if management's logic holds — multiple could compress if sentiment shifts.