Income tax in Spain

Does anyone fully understand the Spanish Income tax system?I have given all of the necessary details to a local Gestor and she has presented me with forms to take to the bank in order to pay our tax. However, I think the tax is very high compared to both the UK and to France, where we lived for the past eight years. When I questioned the Gestor as to how the tax is calculated her response was, basically, "I enter your information into the computer and it tells me what your payment should be .I don't have to understand it!' 

I understand the various income bands which have different percentage taxation levels but, for the life of me, I cannot work out how the allowances are determined as, whatever calculation I use based on available information, I simply cannot come up with any answer remotely near to what the Gestor's computer tells her! I am 71 and have an allowance for that and I am married and I believe my wife also has an allowance and I assume I add those together and then deduct those allowances off our total income and then use the percentage factor but it simply doesn't match anything like what the Gestor has informed us. Is there anyone out there who understands how the tax they are paying is actually calculated? I would be very grateful for any help.

I do not pretend to understand the Spanish Tax system but I do undestand that the combination allowance for two people taxed together is NOT twice the single allowance.  For instance single 7000 combined  say 10500 but to each you would add the earned income allowance (pension is regarded as earned income). There is another thread just started in the General section on this very topic so do have a look round the Forum for all info on tax.

Thanks for that. I do understand that my wife's allowance is not the same as mine. From memory (poor) mine is about 6004€ and my wife something like 3400€ so it's those which are added. To give a rough example, if income is say 30,000€ the allowance deducted would be 9404€ which leaves 20596€ with a tax band of say 28% leaves 5766€ to pay. Seems an awful lot to pay!