import { CalculateMonthCompletionParams } from '../types';
export type Tier = {
    consecutive_months: number;
    min_spend: number;
    max_spend?: number;
    promo_code: string;
};
export declare const findTierForAmount: (amount: number, tiers?: Tier[]) => Tier;
export declare const extractVoucherFromPromoCode: (promoCode: string) => number;
export declare const calculateMonthCompletionValues: ({ data, minAmount, tiers, initialVoucherValue, initialMonthCompletionValue, maxMonths, today, }: CalculateMonthCompletionParams) => {
    monthCompletionValue: number;
    voucherValue: number;
};