Multi-Channel Bookkeeping & Inventory

Per-channel revenue capture is the foundation. Each platform settles in its own way — Amazon every two weeks, Shopify daily or weekly depending on plan, Etsy monthly, eBay every two days under managed payments, TikTok Shop weekly. Each settlement is net of platform-specific fees, refunds, and pass-through tax. Specialist bookkeepers build a per-channel revenue line in the P&L with corresponding fee lines per platform; generalists frequently roll everything into "ecommerce sales" and "platform fees" and lose the visibility that makes management decisions possible.

Inventory tracking across multiple sales channels is the harder problem. The same SKU might be available on Amazon FBA (stock held at Amazon), Shopify (stock held at the seller's warehouse or 3PL), Etsy (typically seller fulfilment), eBay (typically seller fulfilment), and TikTok Shop (mix of FBT and seller fulfilment). The total inventory position has to net across all channels — a sale on Etsy reduces the same SKU's availability everywhere else if the underlying stock is shared. Specialist multi-channel accountants use software (Linnworks, Cin7, Sellbrite, Ordoro, etc.) or custom integrations to track this; generalists frequently track each channel's inventory independently and end up with overselling, stockout, or year-end count discrepancies.

Per-channel profitability analysis is what most multi-channel sellers actually want from their bookkeeping. Amazon FBA orders carry FBA fees plus referral fees plus advertising plus storage. Shopify direct orders carry transaction fees plus payment processing plus your own shipping plus marketing spend. Etsy carries listing fees plus transaction fees plus Offsite Ads. The per-channel margin profile is genuinely different across platforms and across product categories. Specialist bookkeepers build a per-channel P&L with channel-specific fee allocation; generalists treat the lot as a single ecommerce P&L and the seller never knows where the real money is being made.

Cashflow forecasting for ecommerce is a specialism in itself because of the timing patterns. Amazon's 14-day settlement cycle plus the rolling reserve for new sellers can create cash gaps that aren't obvious until they bite. Shopify Capital and Amazon Lending repayments come out of payouts automatically. Seasonal stock buys (especially for Q4-heavy sellers like toys, gifts, seasonal apparel) create large outflows in Q3 that recover only as Q4 sales settle. Specialist multi-channel accountants build 13-week rolling forecasts that capture all these patterns; generalists work from monthly close which is too lagged for ecommerce decision-making.

Year-end inventory count and reconciliation across channels — for a multi-channel seller with stock at Amazon FBA, at a 3PL, and at home/warehouse, the year-end count needs to reconcile each location's recorded inventory against the actual physical or system count. Amazon's Inventory Adjustment Report shows write-offs, removals, and damages that may not have been tracked in the seller's books. The 3PL's monthly inventory report gives the position at their location. The seller-fulfilled stock needs a count. Specialist accountants build the year-end reconciliation as a standard procedure; generalists frequently take the Amazon dashboard view as fact and miss the adjustments.

Channel-shared inventory creating overselling — when the same SKU is listed on Amazon, Shopify, and Etsy with the same underlying stock pool, a sale on one channel needs to update the available quantity on the others. Without integration software (Linnworks, Cin7, Sellbrite) this happens manually and lags, leading to overselling on the slowest-syncing channel. The accounting effect is order cancellations, refunds, and reputation damage; the bookkeeping effect is harder reconciliation because the order existed but the revenue didn't.

Wholesale alongside retail — sellers running wholesale (B2B) channels alongside the retail channels need separate margin and VAT treatment. Wholesale prices are typically 40-60% of retail; the gross margin profile is different; VAT handling can differ if reverse charge applies. Specialist bookkeepers set up wholesale as a separate channel with its own P&L; generalists frequently mix wholesale revenue into the consumer-channel P&L and the margin reporting becomes meaningless.

Sample and PR products — multi-channel sellers running creator partnerships or sending samples for review need to track these as marketing expense at COGS value with corresponding inventory adjustment. The cumulative effect across a year for a sample-heavy seller can be £5-15k of inventory write-down that's frequently missed entirely.

Returns and refunds across platforms — each platform handles returns differently. Amazon FBA accepts returns into your inventory account (sellable, unsellable, or removed). Shopify returns depend on your fulfilment setup. Etsy returns are typically the seller's responsibility to receive and process. Per-channel return rates vary materially (Amazon FBA tends to highest, Etsy lowest for handmade) and the accounting treatment differs across them. Specialist bookkeepers track per-channel return rates and gross-to-net effect; generalists treat returns as an undifferentiated reduction.

Multi-currency settlement — Amazon UK + Amazon US + Amazon DE + Shopify USD = four different settlement currencies. Each conversion to GBP creates realised FX gain or loss. Without per-currency P&L, the FX effect hides inside revenue and the seller can't tell whether margin moved or the pound moved. Specialist bookkeepers build the per-currency picture; generalists work in GBP-equivalent and lose the visibility.