We went over the bridge a couple of days after it opened and paid retrospectively - its not worth me paying £35 for advance registration, I don't intend to use it much (we came back through the tunnel).
I can safely say the software they use is a long way from ready. Here is the text from the recipt, the things I have overwritten are $$$ which are the registration number and financial bits.
Dear Mr. ANONYMOUS $$$$$
MERSEYFLOW PAYMENT RECEIPT
Thank you for contacting merseyflow.
Please see the details of your payment listed below:
Date and Time: 15/10/2017 17:09
Type: PURCHASE
Account Number: $$$$$$$
Payment Type: CREDIT
Card Type: VISA
Card Number: ************$$$$
Reference Number: $$$$$$$$$$$$$$$$$$
VRM No:$$$$$
FJ Number: $$$$$$
Amount: £2.00
Please be advised that you can see how much credit is against your vehicle registration by selecting the following link www.merseyflow.co.uk
If you require further information, visit our website, www.merseyflow.co.uk or alternatively you can telephone us on 01928 878 878, our opening hours are Monday to Friday 8:00am – 8:00pm and Weekends 9:00am – 6:00pm.
Yours sincerely
The Merseyflow Customer Service Team The link they say to check your balance isn't a link at all and isn't correct for your balance, I entered my name so why they call me "anonymous" I have no idea.
It takes quite a bit of time to pay, I guess its easier to put a few journeys worth against your registration but as I have a number of vehicles I'd have to do it for each one.
Its a bit silly having the Merseygateway website but the payment website is Merseyflow????
The registration fee is ridiculous, whilst the fee is only £5 there is a minimum amount of £30 credit you have to put on as well.
I would say that the road link-ups to the bridge on the Runcorn side are excellent, the Widnes side seems a bit weird but that may not be fully sorted out yet.